Cassiar mine, British Columbia

The Cassiar mine was a chrysotile mine on McDame Mountain in northern British Columbia, which Asbestos, the industry's trade journal, placed "200 miles southeast of Whitehorse, near the Yukon border."³ The earliest reports, in the U.S. Bureau of Mines' Minerals Yearbook for 1950, do not name the mine: they say that "diamond drilling established the presence of a deposit of good-quality chrysotile in northern British Columbia" and that Conwest-Exploration Co., Ltd., "planned extensive development work during 1951."¹⁰ The 1951 yearbook said the McDame Creek fiber "is said to be high-quality spinning-grade chrysotile," and the 1955 yearbook described the Cassiar mine as "producing low-iron chrysotile asbestos of strategic importance."^2,4

Getting started

The 1952 yearbook reported that the deposit "is being developed by Cassiar Asbestos Corp., a subsidiary of Conwest Exploration Co.," and that "a mill having a capacity of 250 tons of rock a day was completed in 1952."¹ The sources date the start of production differently: a 1979 item in Asbestos says the company "began asbestos ore production in 1952."³ In May 1953 the trade journal wrote that "the 250-ton talus mill will be completed by July 1, 1953, when steady production is scheduled to commence," and in April 1954 that the company had "started production in a preliminary way" in 1953.^5,7 A 1958 item in the same journal says Cassiar Asbestos "brought its B. C. asbestos property into production in 1954," the year the yearbook says a new mill of "500 tons of mill rock" a day "began operation."^11,12

The mountain, the tramway and the mill

In December 1954 Asbestos described "an asbestos mine ... being carved out of a mountainside at the 6,000 foot level," with a mill "with 70 tons a day capacity ... located on another mountain at an elevation of 3,450 feet"; ore was "bulldozed into a steel shute nearly half a mile long, fed into ore bins, and trucked three and one-half miles to the mill."¹³ In 1956 the company placed in operation "a new aerial tram line at a cost of $1,000,000 to transport asbestos rock from the mine at McDame Mountain to the milling plant."¹⁴ In 1959 the trade journal described the open-cast workings as "steps or benches cut into the sloping spur of McDame Mountain."¹⁵

Mining was seasonal, Asbestos wrote in 1959, with "the consequent restricted mining period due to the severe winter (November to May)"; in 1956 the company had doubled its dry rock storage "to 100,000 tons" so the mill could run "throughout winter months at the current rate of 700 to 750 tons per day."^14,16 In the trade journal and the yearbook the mill kept growing: "1,000 tons daily" in 1958, an expansion "to a daily capacity of 1,500 tons of ore" completed in January 1960, and an addition completed in July 1964 for "the new AY grade."^8,11,17 In September 1975, the yearbook says, the company "started operating a new tramline and primary crusher plant"; the trade journal gave the tramline as "15,370-foot-long" with "a 2,130-foot vertical drop."^18,19

Output and customers

The yearbook reported "shipments of 15,031 short tons of fibers" for 1955, and the next year's yearbook put 1955 at "about 15,000 tons" and 1956 at "more than 20,000 tons of fiber."^2,20 For 1963 the company's annual report, as Asbestos and the yearbook repeated it, said the mine "produced 756,574 tons of ore," and the yearbook gave fiber production as "62,214 tons."^21,22 For 1974 Asbestos reported "92,709 tons of fiber" from the Cassiar mill, and the company gave its 1978 output as "75,135 tons in 1978 compared with 107,060 tons the prior year."^23,24

Asbestos wrote in 1965 that Raybestos-Manhattan "have been the largest consumers of Cassiar spinning fibres since commencement of operations," and in 1978 the company said its customers were "located in 45 different countries."^25,26 Jade was a byproduct: in 1980 the company's sales revenue included "$860,000 received from the sale of jade."²⁷

Owners

The 1962 yearbook still called Conwest Exploration "the parent company."²⁸ In 1979 Asbestos listed the principal shareholders as "Bell Asbestos Mines Ltd. (23.4%), Newmont Mining Corporation (12.9%), Raybestos-Manhattan, Inc. (10%) and James Hardie Industries Ltd. (10%)."³ The company changed its name "effective August 1, 1980, to Cassiar Resources Ltd.," and in December Brinco reported it had acquired "98% of the outstanding shares."²⁷ By April 1981 Brinco had "acquired all of the outstanding shares," and the business was to be run by "the Cassiar Resources Division of Brinco Mining Ltd."²⁹

The people

In May 1953 Asbestos told of "new bunkhouses, staff dwellings, a recreation hall and school" going up in the townsite, and in 1973 it reported that the Cassiar mine employed 450 workers.^5,30 The yearbook for 1975 told of "a 3-week strike in early winter of some 400 workers."¹⁸ In January 1977 the company regretted that "our strike at the Cassiar Mine last summer may have inconvenienced some of our customers."³¹ Another strike began in September 1978: Asbestos dated it from "September 15," the company said it "was settled with the signing of a Collective Agreement on the 15th of January 1979," and the yearbook called it "a 3-month strike."^32,33,34

Dust

The company wrote that by 1976 "much work has been done and much money has been spent at the Cassiar Mine in order to improve environmental conditions and the accommodation in the townsite."³¹ Asbestos reported that "a new changehouse was opened in May" 1977 and a new air system for the mill was to be commissioned in 1978.³⁵ The company said the system "went on stream in May, 1978," bringing "a marked reduction in airborne fiber counts in the working environment," with "the objective of achieving a two-fiber-per-cubic-centimeter level."²⁴

Underground plans, closing and tailings

In 1984, according to the yearbook, a deep drill hole "at least doubled the previously established reserves for the McDame deposit."³⁶ In 1988 Cassiar Mining Corp. "began an underground development program," and the yearbook said ore in the surface mine "is expected to be exhausted by the early 1990's."³⁷ The 1988 yearbook expected production from the underground mine "to begin in 1991 at an annual production rate of 90,000 tons per year," and the 1989 yearbook said that "the mine is expected to become operational in March 1990."^37,38 The U.S. Geological Survey reported in 1998 that "the mine has been closed since 1992, but Minroc planned to wet-process tailings."⁹ In 1999 Minroc Mines Inc. changed its name to Cassiar Mines and Metals Inc. and "initiated production of chrysotile fiber from stockpiles and tailings at its Cassiar site."³⁹ The Survey reported that production at the Cassiar Magnesium Inc. operation, "which began in January 2000, has been suspended following a fire in the mill facility."⁴⁰

The documents report this mine producing asbestos fiber for sale.¹²

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Location

Output the documents report

Figures as printed, in the units each document uses (short tons before about 1990, metric tons after, in most U.S. chapters). Some are a year's output, some a daily rate or a capacity, some a company's total rather than this mine's alone; the statement for that year below says which.

Year	Figure	Source
1954	1,500 tons a day (ore)	13
1955	15,031 short tons of fibers	2
1955	15,000 tons of fiber	20
1956	20,000 tons of fiber	20
1961	675,000 tons of ore mined	41
1962	720,000 tons of ore mined	28
1963	62,214 tons of asbestos fiber	22
1963	756,574 tons of ore	22
1963	756,574 tons of ore	21
1964	66,897 tons of fiber	8
1964	705,000 tons of ore	8
1964	705,205 tons of ore	25
1967	92,093 tons of fiber	42
1968	75,000 tons of fiber per year (planned)	42
1968	75,000 tons of fiber per year (rate)	43
1969	75,000 tons of fiber per year (rate)	44
1969	79,591 tons of fiber	45
1973	100,000 tons of asbestos fiber per year	30
1974	110,000 short tons per year (capacity)	46
1974	92,709 tons of fiber	23
1977	100,000 tons of fiber	35
1978	75,135 tons of fiber	24
1991	90,000 tons per year	37
1998	50,000 metric tons per year	9

Year by year

Every statement about this mine in the documents, in each document's own words, by the year it is about.

1950

• Exploration: “Diamond drilling established the presence of a deposit of good-quality chrysotile in northern British Columbia” (Conwest-Exploration Co., Ltd.), p. 8¹⁰

1951

• Exploration: “planned extensive development work during 1951” (Conwest-Exploration Co., Ltd.), p. 8¹⁰
• Exploration: “the McDame Creek asbestos deposit in northern British Columbia, now being developed by Conwest-Exploration Co., Ltd.” (Conwest-Exploration Co., Ltd.), p. 9⁴
• Fiber: “The fiber is said to be high-quality spinning-grade chrysotile” (Conwest-Exploration Co., Ltd.), p. 9⁴

1952

• Description: “The deposit is the most promising occurrence of spinning fiber noted during recent years” (Cassiar Asbestos Corp.), p. 10¹
• Ownership: “is being developed by Cassiar Asbestos Corp., a subsidiary of Conwest Exploration Co.” (Cassiar Asbestos Corp.), p. 9¹
• Reserves: “Exploratory work indicates the presence of a large body of asbestos-bearing rock having a relatively high fiber content” (Cassiar Asbestos Corp.), p. 10¹
• Mill: “A mill having a capacity of 250 tons of rock a day was completed in 1952” (Cassiar Asbestos Corp.), p. 9¹
• Opened: “began asbestos ore production in 1952” (Cassiar Asbestos Corporation Ltd.), p. 30³

1953

• Opened: “Production is expected in 1953” (Conwest-Exploration Co., Ltd.), p. 9⁴
• Mill: “It was expected that the mill would be in operation by midsummer 1953. A larger mill to handle rock from underground workings is contemplated” (Cassiar Asbestos Corp.), p. 9¹
• Description: “Fibre will be trucked to Whitehorse in the company's own truck fleet” (Cassiar Asbestos Corporation Ltd.), p. 8⁵
• Buyers: “Bell Asbestos Mines Ltd. ... will act as Cassiar agents in the sale of its product” (Cassiar Asbestos Corporation Ltd.), p. 10⁵
• Workforce: “New bunkhouses, staff dwellings, a recreation hall and school ... under construction in the townsite” (Cassiar Asbestos Corporation Ltd.), p. 8⁵
• Exploration: “a bulk sample of some 3,679 tons of asbestos talus material was dried and screened to produce some 334 tons” (Cassiar Asbestos Corporation Ltd.), p. 8⁵
• Exploration: “Cassiar Asbestos Corp., Ltd., McDame Lake, has continued exploratory work” (Cassiar Asbestos Corp., Ltd.), p. 8⁶
• Reserves: “its fiber-bearing rock reserves were estimated late in 1953 at more than 7 million tons” (Cassiar Asbestos Corp., Ltd.), p. 8⁶
• Mill: “An experimental mill was operated, and several hundred tons of 3K and 4K fibers were recovered from the talus accumulation” (Cassiar Asbestos Corp., Ltd.), p. 8⁶
• Opened: “Cassiar Asbestos Corporation started production in a preliminary way at Cassiar, B. C., in the McDame area” (Cassiar Asbestos Corporation Ltd.), p. 14⁷
• Opened: “steady production is scheduled to commence [July 1, 1953]” (Cassiar Asbestos Corporation Ltd.), p. 8⁵
• Output: “3K Fibre 3,780—5,600 tons; 4K Fibre 2,700—4,000 tons [estimated, July 1953 to July 1954]” (Cassiar Asbestos Corporation Ltd.), p. 8⁵
• Mill: “The 250-ton talus mill will be completed by July 1, 1953” (Cassiar Asbestos Corporation Ltd.), p. 8⁵

1954

• Mill: “A new mill having a capacity of 500 tons of rock per day was expected to be completed by June 1954” (Cassiar Asbestos Corp., Ltd.), p. 8⁶
• Reserves: “ore reserves in excess of 7,000,000 tons, or enough to sustain operation on the initial basis for more than 40 years” (Cassiar Asbestos Corporation Ltd.), said by Robert Devlin, manager, Cassiar Asbestos Corporation, as reported by Asbestos (magazine), p. 14⁷
• Description: “An asbestos mine is being carved out of a mountainside at the 6,000 foot level” (Cassiar Asbestos Corporation), p. 57¹³
• Mill: “A mill with 70 tons a day capacity is located on another mountain at an elevation of 3,450 feet” (Cassiar Asbestos Corporation), p. 57¹³
• Output: “ore was taken from the mine at the rate of 1,500 tons a day ... more than 40,000 tons will have been removed” (Cassiar Asbestos Corporation), p. 57¹³
• Description: “an aerial tramway 15,000 feet long, to carry rock from mine to mill, was under construction” (Cassiar Asbestos Corp., Ltd.), as reported by Northern Miner, p. 10¹²
• Opened: “began operation in 1954, at McDame Creek” (Cassiar Asbestos Corp., Ltd.), p. 10¹²
• Buyers: “Substantial quantities are reaching United States markets” (Cassiar Asbestos Corp., Ltd.), p. 10¹²
• Mill: “A new mill having a daily capacity of 500 tons of mill rock was completed ... and began operation in 1954” (Cassiar Asbestos Corp., Ltd.), p. 10¹²
• Opened: “Cassiar Asbestos, which brought its B. C. asbestos property into production in 1954” (Cassiar Asbestos), p. 8¹¹
• Mill: “The company's 500-ton mill is scheduled for completion in July 1954 ... an aerial tramway, 14,950 feet long” (Cassiar Asbestos Corporation Ltd.), p. 14⁷
• Mill: “expansion of the plant to handle 500 tons per day by September 1, 1954” (Cassiar Asbestos Corporation Ltd.), p. 8⁵

1955

• Fiber: “low-iron chrysotile asbestos”, p. 3²
• Worked: “the Cassiar mine, which is producing low-iron chrysotile asbestos of strategic importance”, p. 3²
• Worked: “The company completed its first full year of production in September”, as reported by Northern Miner, p. 12²
• Output: “Shipments of 15,031 short tons of fibers”, p. 12²
• Worked: “Mining at the Cassiar mine ... continued to progress satisfactorily”, p. 12²
• Description: “erection of an aerial tramway begun in 1954”, as reported by Northern Miner, p. 12²
• Output: “about 15,000 tons in 1955”, p. 11²⁰

1956

• Opened: “Mining was begun a month earlier than expected”, p. 11²⁰
• Mill: “the mill, which had a rated capacity of 500 tons of rock, was found capable of milling 750 or more tons per day”, p. 11²⁰
• Output: “output in 1956 reached more than 20,000 tons of fiber compared with about 15,000 tons in 1955”, p. 11²⁰
• Description: “a new aerial tram line at a cost of $1,000,000 to transport asbestos rock from the mine at McDame Mountain to the milling plant” (Cassiar Asbestos Corporation), p. 16¹⁴
• Mill: “Cassiar Asbestos Corporation doubled dry rock storage capacity to 100,000 tons ... operation of the mill throughout winter months at the current rate of 700 to 750 tons per day” (Cassiar Asbestos Corporation), p. 16¹⁴

1957

• Ownership: “It acquired 3 additional asbestos properties, on 1 of which development work was conducted” (Cassiar Asbestos Corp., Ltd.), p. 8⁴⁷
• Mill: “increased its milling capacity and improved its mining and transportation facilities” (Cassiar Asbestos Corp., Ltd.), p. 8⁴⁷

1958

• Mill: “has increased its mill capacity to 1,000 tons daily” (Cassiar Asbestos), p. 8¹¹
• Description: “the biggest field and the most important is in British Columbia as is clearly indicated by the high value of the fibre being recovered from the Cassiar Mine”, p. 6⁴⁸
• Exploration: “Development at Cassiar Asbestos in British Columbia extended the southern limit of the ore body” (Cassiar Asbestos), as reported by Northern Miner (Toronto), p. 10⁴⁹
• Mill: “The Cassiar mill treated an average of 1065 tons or ore per calendar day (in 1958) from stocks of accumulated ore amounting to about 100,000 tons in dry-rock storage” (Cassiar Asbestos Corporation), p. 6¹⁶

1959

• Description: “The open-cast workings take the form of steps or benches cut into the sloping spur of McDame Mountain, situated some 6,000 feet above sea level” (Cassiar Asbestos Corporation Ltd.), p. 18¹⁵
• Description: “The Cassiar Mine (Cassiar Asbestos Corporation Ltd.) in northern British Columbia, is small and of totally different aspect physically” (Cassiar Asbestos Corporation Ltd.), p. 18¹⁵
• Idle: “the consequent restricted mining period due to the severe winter (November to May)” (Cassiar Asbestos Corporation), p. 6¹⁶
• Reserves: “the estimated reserves at Cassiar in British Columbia and at the Munro Mine in Ontario, together amount to over 10,000,000 tons”, p. 6¹⁶
• Mill: “installation of mill equipment to increase daily capacity from 1,000 to 1,500 tons of ore” (Cassiar Asbestos Corp., Ltd.), as reported by Northern Miner (Toronto), p. 6⁵⁰

1960

• Mill: “The Cassiar mill is designed on conventional lines and allows for increased capacity as the ore output is increased from the mining development”, p. 12⁵¹
• Mill: “Expansion of the Cassiar mills to a daily capacity of 1,500 tons of ore was completed in January” (Cassiar Asbestos Corp., Ltd.), p. 7¹⁷
• Output: “Increased sales ... were due largely to stronger demand for cement-grade product” (Cassiar Asbestos Corp., Ltd.), p. 7¹⁷

1961

• Mill: “Additional equipment was installed in the mill to improve recoveries of AK and AX grades” (Cassiar Asbestos Corp., Ltd.), p. 9⁴¹
• Mill: “582,000 tons milled” (Cassiar Asbestos Corp., Ltd.), p. 9⁴¹
• Exploration: “Exploration holes on the northern extension of the deposit went as deep as 105 feet” (Cassiar Asbestos Corp., Ltd.), p. 9⁴¹
• Buyers: “Sales of short cement-grade fibers continued to rise ... with stronger trade in European markets” (Cassiar Asbestos Corp., Ltd.), p. 9⁴¹
• Exploration: “Development on the 5,700-foot level showed persistent size and grade of ore body” (Cassiar Asbestos Corp., Ltd.), p. 9⁴¹
• Output: “675,000 tons of ore was mined” (Cassiar Asbestos Corp., Ltd.), p. 9⁴¹

1962

• Ownership: “The parent company, Conwest Exploration Co., Ltd.” (Conwest Exploration Co., Ltd.), p. 9²⁸
• Mill: “Plans were made to move the crushing plant to a lower level and to install a larger crusher” (Cassiar Asbestos Corp. Ltd.), p. 9²⁸
• Output: “720,000 tons of ore was mined” (Cassiar Asbestos Corp. Ltd.), p. 9²⁸
• Reserves: “Ore reserves were sufficient for 30 years of production at the current rate” (Cassiar Asbestos Corp. Ltd.), p. 9²⁸
• Worked: “Operations ... continued through the winter months” (Cassiar Asbestos Corp. Ltd.), p. 9²⁸
• Mill: “Ore milled totaled 535,000 tons” (Cassiar Asbestos Corp. Ltd.), p. 9²⁸

1963

• Mill: “the mill will be expanded to recover a new cement grade, tentatively named Cassiar AY” (Cassiar Asbestos Corp., Ltd.), as reported by Northern Miner (Toronto), p. 8²²
• Mill: “Ore and concentrate milled totaled 588,733 tons” (Cassiar Asbestos Corp., Ltd.), p. 8²²
• Description: “Stripping operations removed from the pit and peak 2,824,197 tons of waste rock” (Cassiar Asbestos Corp., Ltd.), as reported by Cassiar Asbestos Corporation annual report, p. 8²²
• Output: “Production of asbestos fiber amounted to 62,214 tons, an increase of 8 percent over 1962 production” (Cassiar Asbestos Corp., Ltd.), as reported by Cassiar Asbestos Corporation annual report, p. 8²²
• Output: “the mine produced 756,574 tons of ore” (Cassiar Asbestos Corp., Ltd.), as reported by Cassiar Asbestos Corporation annual report, p. 8²²
• Opened: “opening of several new mines producing principally asbestos-cement-grade fiber” (Cassiar Asbestos Corp., Ltd.), as reported by Cassiar Asbestos Corporation annual report, p. 8²²
• Output: “During 1963, Cassiar's mine produced 756,574 tons of ore” (Cassiar Asbestos Corporation Limited), said by Cassiar Asbestos Corporation Limited, as reported by Asbestos (magazine), p. 28²¹
• Mill: “The mill treated a record 588,733 tons of mine ore and concentrate” (Cassiar Asbestos Corporation Limited), said by Cassiar Asbestos Corporation Limited, as reported by Asbestos (magazine), p. 28²¹
• Reserves: “with sufficient ore indicated within the presently planned pit limits for 29 years production at the present rate” (Cassiar Asbestos Corporation Limited), said by Cassiar Asbestos Corporation Limited, as reported by Asbestos (magazine), p. 28²¹

1964

• Mill: “10,000 to 15,000 tons of fibre to be known as Cassiar AY can be recovered annually ... additions to the mill ... will be completed in the fall of 1964” (Cassiar Asbestos Corporation Limited), said by Cassiar Asbestos Corporation Limited, as reported by Asbestos (magazine), p. 28²¹
• Output: “Cassiar accounted for approximately 5 percent of the quantity and 10 percent of value of total Canadian exports” (Cassiar Asbestos Corp., Ltd.), as reported by Cassiar Asbestos Corp. annual report, p. 6⁸
• Output: “Production of fiber was 66,897 tons, an increase of 7 percent over 1963” (Cassiar Asbestos Corp., Ltd.), as reported by Cassiar Asbestos Corp. annual report, p. 6⁸
• Fiber: “Chrysotile crudes from ... Cassiar Asbestos Corp., Ltd., McDame Lake” (Cassiar Asbestos Corp., Ltd.), as reported by American Mineralogist, p. 10⁸
• Output: “the mine produced 705,000 tons of ore” (Cassiar Asbestos Corp., Ltd.), as reported by Cassiar Asbestos Corp. annual report, p. 6⁸
• Mill: “Ore and concentrate milled totaled 588,000 tons” (Cassiar Asbestos Corp., Ltd.), as reported by Cassiar Asbestos Corp. annual report, p. 6⁸
• Mill: “the mill treated 587,908 tons of ore and concentrate” (Cassiar Asbestos Corporation Limited), said by Cassiar Asbestos Corporation Limited, as reported by Asbestos (magazine), p. 25²⁵
• Output: “During 1964, Cassiar's mine produced 705,205 tons of ore” (Cassiar Asbestos Corporation Limited), said by Cassiar Asbestos Corporation Limited, as reported by Asbestos (magazine), p. 25²⁵
• Mill: “An addition to the mill completed in July 1964 provided for production of the new AY grade” (Cassiar Asbestos Corp., Ltd.), as reported by Cassiar Asbestos Corp. annual report, p. 6⁸

1965

• Buyers: “Raybestos-Manhattan have been the largest consumers of Cassiar spinning fibres” (Cassiar Asbestos Corporation Limited), p. 6²⁵
• Worked: “the Cassiar mine will run at full capacity throughout the year” (Cassiar Asbestos Corporation Limited), p. 6²⁵
• Description: “working in frozen ground”, as reported by Canadian Min. and Met. Bull., p. 9⁵²
• Description: “Drilling and blasting methods employed at the Cassiar mine”, as reported by Canadian Min. and Met. Bull., p. 9⁵²

1966

• Worked: “operations at the Cassiar Mine are proceeding as anticipated” (Cassiar Asbestos Corporation Limited), said by Cassiar Asbestos Corporation Limited, as reported by Asbestos (magazine), p. 26⁵³

1967

• Output: “The mill treated 756,787 tons of ore and concentrate and produced 92,093 tons of fiber” (Cassiar Asbestos Corporation Limited), said by Cassiar Asbestos Corporation Limited, as reported by Asbestos (magazine), p. 23⁴²
• Reserves: “the probable ore reserves within the presently planned pit limits ... are 26,000,000 tons” (Cassiar Asbestos Corporation Limited), said by Cassiar Asbestos Corporation Limited, as reported by Asbestos (magazine), p. 23⁴²

1968

• Output: “production from the Cassiar Mine during 1968 will be reduced to its normal operating rate of approximately 75,000 tons of fiber per year” (Cassiar Asbestos Corporation Limited), said by Cassiar Asbestos Corporation Limited, as reported by Asbestos (magazine), p. 23⁴²
• Output: “reduced production at its Cassiar Mine to the originally scheduled rate of 75,000 tons of asbestos fiber per year” (Cassiar Asbestos Corporation Limited), p. 12⁴³

1969

• Output: “Cassiar is being maintained at an annual rate of 75,000 tons of fiber” (Cassiar Asbestos Corporation Limited), p. 24⁴⁴
• Mill: “completion was scheduled for December 1970” (Cassiar Asbestos Corp. Ltd.), as reported by Cassiar Asbestos Corporation Ltd. Annual Report, p. 8⁵⁴
• Mill: “plans to expand mill capacity ... from 75,000 tons of fiber annually to 100,000 tons” (Cassiar Asbestos Corp. Ltd.), as reported by Cassiar Asbestos Corporation Ltd. Annual Report, p. 8⁵⁴
• Description: “The shear blasting technique now being tested is proving quite successful” (Cassiar Asbestos Corporation Limited), said by Cassiar Asbestos Corporation Limited, as reported by Asbestos (magazine), p. 49⁴⁵
• Reserves: “Probable ore reserves ... are estimated at 24,250,000 tons” (Cassiar Asbestos Corporation Limited), said by Cassiar Asbestos Corporation Limited, as reported by Asbestos (magazine), p. 49⁴⁵
• Output: “716,118 tons of asbestos ore were mined ... produced 79,591 tons of fiber” (Cassiar Asbestos Corporation Limited), said by Cassiar Asbestos Corporation Limited, as reported by Asbestos (magazine), p. 49⁴⁵

1970

• Mill: “is expanding mill capacity ... from 75,000 tons to 100,000 tons of fiber per year” (Cassiar Asbestos Corporation Ltd.), p. 18⁵⁵

1971

• Mill: “constructed a new asbestos processing mill ... capable of processing 3000 tons of ore per day” (Cassiar Asbestos Corporation Ltd.), p. 8⁵⁶

1973

• Output: “Each mine produces slightly over 100,000 tons of asbestos fiber per year” (Cassiar Asbestos Corporation Ltd.), p. 14³⁰
• Workforce: “Each mine produces slightly over 100,000 tons of asbestos fiber per year and employs 450 and 350 workers, respectively” (Cassiar Asbestos Corporation Ltd.), p. 14³⁰

1974

• Output: “Fiber-producing capacity 110,000 (short tons per year)” (Cassiar Asbestos Corp. Ltd (partial interest)), as reported by Economic Analysis of Proposed Effluent Guidelines, The Asbestos Products Manufacturing Industry, EPA-230/1-73-001, p. 8⁴⁶
• Ownership: “Raybestos-Manhattan, Inc | Cassiar Asbestos Corp. Ltd (partial interest) | 110,000” (Cassiar Asbestos Corp. Ltd (partial interest)), as reported by Economic Analysis of Proposed Effluent Guidelines, The Asbestos Products Manufacturing Industry, EPA-230/1-73-001, p. 8⁴⁶
• Reserves: “Probable ore reserves at the end of 1974 were calculated at about 22-million tons” (Cassiar Asbestos Corporation Ltd.), p. 31²³
• Output: “In 1974, 92,709 tons of fiber were produced at the Cassiar Mill” (Cassiar Asbestos Corporation Ltd.), p. 31²³

1975

• Mill: “The 15,370-foot-long tramline, which has a 2,130-foot vertical drop, can feed the concentrator at an approximate hourly rate of 300 tons; ore extends beneath the horizon of the open-pit” (Cassiar Asbestos Corporation Ltd.), as reported by Northern Miner, p. 32¹⁹
• Description: “the Cassiar Mine at McDame Mountain ... yields fibers equivalent to QAMA Grades 1-6” (Cassiar Asbestos Corporation Ltd.), p. 31²³
• Reserves: “A 3-year drilling program at Cassiar has proved a minimum 20-year life as an open-pit operation” (Cassiar Asbestos Corporation Ltd.), p. 32²³
• Mill: “installation this year of a new primary concentrator and a 15,370-foot-long aerial tramline” (Cassiar Asbestos Corporation Ltd.), p. 32²³
• Idle: “a 3-week strike in early winter” (Cassiar Asbestos Corp. Ltd.), p. 9¹⁸
• Dust and health: “strike ... of some 400 workers over health and safety conditions” (Cassiar Asbestos Corp. Ltd.), p. 9¹⁸
• Mill: “started operating a new tramline and primary crusher plant at its Cassiar, British Columbia, mine in September” (Cassiar Asbestos Corp. Ltd.), p. 9¹⁸

1976

• Description: “At Cassiar a new waste phase with wider operating benches has been started and the company is proceeding with flattening the overall slope of the footwall” (Cassiar Asbestos Corporation Ltd.), p. 31⁵⁷
• Idle: “We regret that our strike at the Cassiar Mine last summer may have inconvenienced some of our customers” (Cassiar Asbestos Corporation Ltd.), said by Cassiar Asbestos Corporation Ltd., p. 8³¹
• Dust and health: “Much work has been done and much money has been spent at the Cassiar Mine in order to improve environmental conditions and the accommodation in the townsite” (Cassiar Asbestos Corporation Ltd.), said by Cassiar Asbestos Corporation Ltd., p. 8³¹

1977

• Description: “called for tenders ... to move 70,000 tons of asbestos per year to Vancouver from Stewart; its current shipping method, i.e., through Skagway, Alaska” (Cassiar Asbestos Corporation Ltd.), as reported by The Globe & Mail, p. 38⁵⁸
• Dust and health: “A new changehouse was opened in May and commissioning of a new air system for the mill will take place during the first quarter of 1978” (Cassiar Asbestos Corporation Ltd.), p. 28³⁵
• Reserves: “Minable ore reserves at the beginning of 1977 were 18-million tons” (Cassiar Asbestos Corporation Ltd.), p. 28³⁵
• Output: “should yield about 100,000 tons of fiber this year. Minable ore reserves at the beginning of 1977 were 18-million tons” (Cassiar Asbestos Corporation Ltd.), p. 28³⁵
• Buyers: “Cassiar's customers are located in 45 different countries; container loads ... from the mine site to the British Columbia port of Stewart, and on to Vancouver by tug and barge” (Cassiar Asbestos Corporation Ltd.), said by Cassiar Asbestos Corporation Ltd., as reported by Asbestos (magazine), p. 32²⁶
• Reserves: “ore reserves at year-end 1977, mineable by open pit methods, were calculated at 16,277,000 tons” (Cassiar Asbestos Corporation Ltd.), p. 32³²

1978

• Dust and health: “A continued improvement in airborne fiber counts is being achieved” (Cassiar Asbestos Corporation Ltd.), p. 32³²
• Dust and health: “During 1978 the new mill air system was brought on line ... has resulted in improved environmental conditions” (Cassiar Asbestos Corporation Ltd.), said by Cassiar Asbestos Corporation Ltd., p. 8⁵⁹
• Output: “Fiber production reached 75,135 tons in 1978 compared with 107,060 tons the prior year” (Cassiar Asbestos Corporation Ltd.), said by Cassiar Asbestos Corporation Ltd., as reported by Asbestos (magazine), p. 43²⁴
• Idle: “Cassiar Asbestos Corp.'s 3-month strike in British Columbia” (Cassiar Asbestos Corp.), p. 11³⁴
• Dust and health: “The new mill air system went on stream in May, 1978 ... a marked reduction in airborne fiber counts; objective of achieving a two-fiber-per-cubic-centimeter level” (Cassiar Asbestos Corporation Ltd.), said by Cassiar Asbestos Corporation Ltd., as reported by Asbestos (magazine), p. 43²⁴
• Idle: “Collective Agreement negotiations at Cassiar resulted in a strike in September and the mine is presently shut down” (Cassiar Asbestos Corporation Ltd.), said by Cassiar Asbestos Corporation Ltd., p. 8⁵⁹
• Idle: “a 3-month strike at its Cassiar pit in British Columbia beginning in September” (Cassiar Asbestos Corp.), p. 11³⁴
• Idle: “The strike, which commenced in September 1978, was settled with the signing of a Collective Agreement on the 15th of January 1979” (Cassiar Asbestos Corporation Ltd.), said by Cassiar Asbestos Corporation Ltd., p. 10³³
• Idle: “Cassiar's operations had been shut down due to strike action which began September 15” (Cassiar Asbestos Corporation Ltd.), p. 32³²
• Reserves: “At December 31, 1978, ore reserves mineable by open pit methods were calculated at 15.3-million tons” (Cassiar Asbestos Corporation Ltd.), p. 31³

1979

• Mill: “The milling complex can treat over 3300 tons per day and is capable of producing some 135,000 tons of fiber annually” (Cassiar Asbestos Corporation Ltd.), as reported by Jones Heward & Co. Ltd., p. 30³
• Description: “Over $77-million has been spent with more than half going to environmental improvements and additional waste mining in the pit” (Cassiar Asbestos Corporation Ltd.), as reported by Jones Heward & Co. Ltd., p. 30³
• Ownership: “Principal shareholders in Cassiar Asbestos are Bell Asbestos Mines Ltd. (23.4%), Newmont Mining Corporation (12.9%), Raybestos-Manhattan, Inc. (10%) and James Hardie Industries Ltd. (10%)” (Bell Asbestos Mines Ltd.; Newmont Mining Corporation; Raybestos-Manhattan, Inc.; James Hardie Industries Ltd.), as reported by Jones Heward & Co. Ltd., p. 31³

1980

• Exploration: “Diamond drilling from the exploration adit indicates a faulted extension or a separate ore lens containing over 5-million tons of asbestos-bearing material” (Cassiar Resources Ltd.), p. 24²⁷
• Description: “$860,000 received from the sale of jade, a byproduct in the mining of asbestos ores” (Cassiar Resources Ltd.), p. 24²⁷
• Ownership: “Brinco Ltd. acquired 98% of the outstanding shares of Cassiar Resources” (Brinco Ltd.), p. 8⁶⁰
• Ownership: “Cassiar Asbestos Corporation Ltd. officially changed its name, effective August 1, 1980, to Cassiar Resources Ltd.” (Cassiar Resources Ltd.), p. 22²⁷
• Ownership: “In December Brinco reported it had acquired 98% of the outstanding shares of Cassiar Resources; T&N sold its 23.4% interest in Cassiar for C$20.6-million” (Brinco Ltd.), p. 22²⁷

1981

• Ownership: “Brinco Ltd. ... has now acquired all of the outstanding shares of Cassiar Resources; Future business activities will be conducted by the Cassiar Resources Division of Brinco Mining Ltd.” (Brinco Mining Ltd.), p. 23²⁹

1982

• Idle: “closed its asbestos mine in British Columbia for 7 weeks to repair its tramway” (Cassiar Resources Ltd.), p. 7⁶¹

1984

• Reserves: “the 15-million-ton McDame deposit” (Brinco Mining Ltd.), as reported by The Northern Miner, p. 6³⁶
• Reserves: “This deep hole at least doubled the previously established reserves for the McDame deposit” (Brinco Mining Ltd.), as reported by The Northern Miner, p. 6³⁶
• Reserves: “the grade of the deposit is similar to the main Cassiar ore body, the unit value of the ore was expected to be higher” (Brinco Mining Ltd.), as reported by The Northern Miner, p. 6³⁶
• Exploration: “a deep drill hole, which was collared 750 feet southeast of the 15-million-ton McDame deposit” (Brinco Mining Ltd.), as reported by The Northern Miner, p. 6³⁶
• Reserves: “increased the expected life of its Cassiar asbestos operations in British Columbia severalfold” (Brinco Mining Ltd.), as reported by The Northern Miner, p. 6³⁶

1988

• Exploration: “began an underground development program at its McDame Mine” (Cassiar Mining Corp.), as reported by Industrial Minerals (London), p. 5³⁷
• Reserves: “ore in the currently operating surface mine is expected to be exhausted by the early 1990's” (Cassiar Mining Corp.), as reported by Industrial Minerals (London), p. 5³⁷
• Description: “approximately 70% of the asbestos produced from the mine will be grade 4” (Cassiar Mining Corp.), as reported by Industrial Minerals (London), p. 5³⁷

1989

• Reserves: “Reserves in the open pit are sufficient to continue operation through late 1990” (Cassiar Mining Co.), as reported by Mining Journal, p. 5³⁸
• Exploration: “Developmental work continued on the underground portion” (Cassiar Mining Co.), as reported by Mining Journal, p. 5³⁸

1990

• Opened: “expected to become operational in March 1990” (Cassiar Mining Co.), as reported by Mining Journal, p. 5³⁸

1991

• Output: “an annual production rate of 90,000 tons per year” (Cassiar Mining Corp.), as reported by Industrial Minerals (London), p. 5³⁷

1992

• Closed: “closed since 1992” (Minroc Mines Inc.), as reported by Minroc Mines Inc. website (http://www.minroc.com/prmain.htm), p. 2⁹

1998

• Mill: “bring an existing dry-processing facility back on-line, anticipating capacity to be 18,000 t/yr of long-fiber chrysotile” (Minroc Mines Inc.), as reported by Minroc Mines Inc. website (http://www.minroc.com/prmain.htm), p. 2⁹
• Exploration: “completed its study of the Cassiar asbestos mine and plant” (Minroc Mines Inc.), as reported by Minroc Mines Inc. website (http://www.minroc.com/prmain.htm), p. 2⁹
• Output: “the anticipated production will be 50,000 metric tons per year” (Minroc Mines Inc.), as reported by Minroc Mines Inc. website (http://www.minroc.com/prmain.htm), p. 2⁹
• Reserves: “tailings that average 4.2% chrysotile” (Minroc Mines Inc.), as reported by Minroc Mines Inc. website (http://www.minroc.com/prmain.htm), p. 2⁹

1999

• Worked: “initiated production of chrysotile fiber from stockpiles and tailings at its Cassiar site” (Cassiar Mines and Metals Inc.), as reported by Cassiar Mines and Metals Inc. press release, p. 2³⁹
• Description: “agreement with Aluminum of Korea Ltd. ... to develop a magnesium plant at the Cassiar site, using stockpiled serpentinite” (Cassiar Mines and Metals Inc.), as reported by Cassiar Mines and Metals Inc. press release, p. 2³⁹
• Ownership: “Minroc Mines Inc., which owns a chrysotile mine and mill ... changed its name to Cassiar Mines and Metals Inc.” (Cassiar Mines and Metals Inc.), as reported by Cassiar Mines and Metals Inc. press release, p. 2³⁹

2000

• Buyers: “customers in Dubai, India, Indonesia, Iran, Japan, Sri Lanka, and Thailand” (Cassiar Magnesium Inc.), p. 3⁴⁰
• Opened: “which began in January 2000” (Cassiar Magnesium Inc.), as reported by North American Minerals News; Canada NewsWire, p. 3⁴⁰
• Mill: “installation of a wet-processing plant that would bring annual capacity to 50,000 metric tons per year” (Cassiar Magnesium Inc.), p. 3⁴⁰
• Description: “proceeding with its development of a facility to process serpentine tailings for magnesium” (Cassiar Magnesium Inc.), as reported by North American Minerals News; Canada NewsWire, p. 3⁴⁰
• Idle: “has been suspended following a fire in the mill facility” (Cassiar Magnesium Inc.), as reported by North American Minerals News; Canada NewsWire, p. 3⁴⁰

In court opinions

Court opinions in our case-law library that name this mine, by how they concern it. A search found every one that names the mine and an AI reader sorted them; the quotation, checked word for word against the text, shows where. Those that name the mine only in passing or in a reference list are left out.

The mine’s fiber in products (2)

• Gardner v. Asbestos Corp., Ltd. (1986): “The motion is based upon the contention that the statute of repose bars recovery for injuries caused by exposure to asbestos sold by the defendant more than six (6) years before the commencement of the lawsuit.”
• Gutierrez v. Cassiar Mining Corp. (1998): “occupational exposure to asbestos at a cement manufacturing plant for which defendant Cassiar Mining Corporation (Cassiar) was the supplier of asbestos fiber.”

In medical studies

Medical studies in our research library that name this mine, by how they concern it. A search found every one that names the mine and an AI reader sorted them; the quotation, checked word for word against the text, shows where. Those that name the mine only in passing or in a reference list are left out.

Studies of the mine’s fiber (13)

• Atkinson AW 1970: Estimation of fibril lengths in chrysotile asbestos fibres
• Barbeau C 1985: Metallic elements in crude and milled chrysotile asbestos from Quebec: “Barbeau. this study; Monkman, Monkman (1975). Cassiar mine is in British Columbia. METALS IN CHRYSOTILE ASBESTOS 279”
• Davis JM 1973: Experimental studies on the effects of heated chrysotile asbestos and automobile brake lining dust injected into the body cavities of mice: “Samples of high grade Cassiar chrysotile asbestos were heated in an electric tube furnace for 4 hr at temperatures of either 400°C 600°C 800°C or 1,OOO”C.”
• Helsen JA 1989: Surface characteristics of asbestos fibers released from asbestos- cement products
• Holmes A 1971: Determination of iron, chromium, cobalt, nickel, and scandium in asbestos by neutron activation analysis: “The highest levels of chrom- ium and scandium were found in chrysotile from the Cassiar mine”
• Holmes EP 2014: The effects of naturally occurring acids on the surface properties of chrysotile asbestos: “chrysotile from the Cassiar Mine, Brit- ish Columbia, Canada, a high-grade chrysotile fibrous- matted-ore was used as the reference (Grade AY).”
• Lavkulich LM 2014: Effects of natural acids on surface properties of asbestos minerals and kaolinite: “and a sample of chrysotile was provided by Holmes[21] from the Cassiar Mine (YT, Canada).”
• McCrone WC 1974: Detection and identification of asbestos by microscopical dispersion staining
• Morgan A 1973: Some observations on the distribution of trace metals in chrysotile asbestos: “A sample of chrysotile from the Cassiar Mine in British Columbia used in an OECD project on non-metallic minerals.”
• Morgan A 1997: Acid leaching studies of chrysotile asbestos from mines in the Coalinga region of California and from Quebec and British Columbia
• Schnitzer RJ 1970: Asbestos hemolysis: “The tests were carried out with the chrysotile varieties Carey (No. 7C) and Cassiar (No. 8C) in the active, air-jet-milled form.”
• Takata A 2009: Forsterite exposure causes less oxidative DNA damage and lung injury than chrysotile exposure in rats: “Fibers of less than 250 µm in length were separated from CH (grade AX) produced by Cassiar Mining Corp., British Columbia, Canada.”
• Takata A 2011: Effectiveness of serum megakaryocyte potentiating factor in evaluating the effects of chrysotile and its heated products on respiratory organs: “Fibers of less than 250 μm in length were separated from CH (grade AX) produced by Cassiar Mining Corp. (British Columbia, Canada).”

Other names

Documents call this mine “Cassiar mine”, “Cassiar mine on McDame Mountain”, “McDame Lake”, “Cassiar, British Columbia, mine”, “Cassiar pit”, “Cassiar asbestos operations”, “asbestos mine in British Columbia”, “McDame Mine”, “McDame asbestos mine”, “Cassiar asbestos mine”, “Cassiar site”, “Cassiar Magnesium Inc. operation”, “Cassiar Mine”, “Cassiar Asbestos Mine”, “McDame Creek asbestos deposit”, “deposit of good-quality chrysotile in northern British Columbia”, “McDame deposit”.

See also

• Cassiar Mine in the Lexicon
• Cassiar Asbestos Corp., Ltd.: the company's documents, people, products and plants
• Raybestos-Manhattan, Inc: the company's history, documents, people, products and plants
• All asbestos mines

References

1. Minerals Yearbook: Asbestos Chapters, 1952 (January 1, 1953), pp. 9–10.
2. Minerals Yearbook: Asbestos Chapters, 1955 (January 1, 1956), pp. 3, 12.
3. Asbestos Magazine, 1979, December 1979 (December 1, 1979), pp. 30–31.
4. Minerals Yearbook: Asbestos Chapters, 1951 (January 1, 1952), p. 9.
5. Asbestos Magazine, 1953, May 1953 (May 1, 1953), pp. 8, 10.
6. Minerals Yearbook: Asbestos Chapters, 1953 (January 1, 1954), p. 8.
7. Asbestos Magazine, 1954, April 1954 (April 1, 1954), p. 14.
8. Minerals Yearbook: Asbestos Chapters, 1964 (January 1, 1965), pp. 6, 10.
9. Minerals Yearbook: Asbestos Chapters, 1998 (January 1, 1999), p. 2.
10. Minerals Yearbook: Asbestos Chapters, 1950 (January 1, 1951), p. 8.
11. Asbestos Magazine, 1958, April 1958 (April 1, 1958), p. 8.
12. Minerals Yearbook: Asbestos Chapters, 1954 (January 1, 1955), p. 10.
13. Asbestos Magazine, 1954, December 1954 (December 1, 1954), p. 57.
14. Asbestos Magazine, 1957, April 1957 (April 1, 1957), p. 16.
15. Asbestos Magazine, 1959, January 1959 (January 1, 1959), p. 18.
16. Asbestos Magazine, 1959, September 1959 (September 1, 1959), p. 6.
17. Minerals Yearbook: Asbestos Chapters, 1960 (January 1, 1961), p. 7.
18. Minerals Yearbook: Asbestos Chapters, 1975 (January 1, 1976), p. 9.
19. Asbestos Magazine, 1975, September 1975 (September 1, 1975), p. 32.
20. Minerals Yearbook: Asbestos Chapters, 1956 (January 1, 1957), p. 11.
21. Asbestos Magazine, 1964, April 1964 (April 1, 1964), p. 28.
22. Minerals Yearbook: Asbestos Chapters, 1963 (January 1, 1964), p. 8.
23. Asbestos Magazine, 1975, December 1975 (December 1, 1975), pp. 31–32.
24. Asbestos Magazine, 1979, July 1979 (July 1, 1979), p. 43.
25. Asbestos Magazine, 1965, April 1965 (April 1, 1965), pp. 6, 25.
26. Asbestos Magazine, 1978, May 1978 (May 1, 1978), p. 32.
27. Asbestos Magazine, 1981, January 1981 (January 1, 1981), pp. 22, 24.
28. Minerals Yearbook: Asbestos Chapters, 1962 (January 1, 1963), p. 9.
29. Asbestos Magazine, 1981, April 1981 (April 1, 1981), p. 23.
30. Asbestos Magazine, 1973, April 1973 (April 1, 1973), p. 14.
31. Asbestos Magazine, 1977, January 1977 (January 1, 1977), p. 8.
32. Asbestos Magazine, 1978, December 1978 (December 1, 1978), p. 32.
33. Asbestos Magazine, 1980, February 1980 (February 1, 1980), p. 10.
34. Minerals Yearbook: Asbestos Chapters, 1978–79 (January 1, 1980), p. 11.
35. Asbestos Magazine, 1977, December 1977 (December 1, 1977), p. 28.
36. Minerals Yearbook: Asbestos Chapters, 1984 (January 1, 1985), p. 6.
37. Minerals Yearbook: Asbestos Chapters, 1988 (January 1, 1989), p. 5.
38. Minerals Yearbook: Asbestos Chapters, 1989 (January 1, 1990), p. 5.
39. Minerals Yearbook: Asbestos Chapters, 1999 (January 1, 2000), p. 2.
40. Minerals Yearbook: Asbestos Chapters, 2000 (January 1, 2001), p. 3.
41. Minerals Yearbook: Asbestos Chapters, 1961 (January 1, 1962), p. 9.
42. Asbestos Magazine, 1968, May 1968 (May 1, 1968), p. 23.
43. Asbestos Magazine, 1968, December 1968 (December 1, 1968), p. 12.
44. Asbestos Magazine, 1969, December 1969 (December 1, 1969), p. 24.
45. Asbestos Magazine, 1970, June 1970 (June 1, 1970), p. 49.
46. Minerals Yearbook: Asbestos Chapters, 1974 (January 1, 1975), p. 8.
47. Minerals Yearbook: Asbestos Chapters, 1957 (January 1, 1958), p. 8.
48. Asbestos Magazine, 1958, October 1958 (October 1, 1958), p. 6.
49. Minerals Yearbook: Asbestos Chapters, 1958 (January 1, 1959), p. 10.
50. Minerals Yearbook: Asbestos Chapters, 1959 (January 1, 1960), p. 6.
51. Asbestos Magazine, 1960, March 1960 (March 1, 1960), p. 12.
52. Minerals Yearbook: Asbestos Chapters, 1965 (January 1, 1966), p. 9.
53. Asbestos Magazine, 1966, September 1966 (September 1, 1966), p. 26.
54. Minerals Yearbook: Asbestos Chapters, 1969 (January 1, 1970), p. 8.
55. Asbestos Magazine, 1970, December 1970 (December 1, 1970), p. 18.
56. Asbestos Magazine, 1971, December 1971 (December 1, 1971), p. 8.
57. Asbestos Magazine, 1976, December 1976 (December 1, 1976), p. 31.
58. Asbestos Magazine, 1977, November 1977 (November 1, 1977), p. 38.
59. Asbestos Magazine, 1979, January 1979 (January 1, 1979), p. 8.
60. Minerals Yearbook: Asbestos Chapters, 1980 (January 1, 1981), p. 8.
61. Minerals Yearbook: Asbestos Chapters, 1982 (January 1, 1983), p. 7.