WEBVTT NOTE Machine transcript of the film's sound; not yet checked. 1 00:00:30.860 --> 00:00:34.600 It's still fresh and new looking after more than four and a half billion years in space. 2 00:00:35.000 --> 00:00:40.780 But we know if we travel back far enough in time that the 3 00:00:40.780 --> 00:00:44.160 seemingly ageless planet Earth has seen many changes. 4 00:00:46.200 --> 00:00:48.180 It had an especially violent beginning. 5 00:00:48.600 --> 00:00:53.880 So violent, in fact, that any solid minerals existing in the first billion years 6 00:00:53.880 --> 00:00:55.280 have long since vanished. 7 00:00:55.920 --> 00:01:00.640 Probably they were melted down in the heat, lost in the mists of early creation. 8 00:01:01.640 --> 00:01:06.040 Throughout the Earth's lifetime, the cooler surface has often yielded to the 9 00:01:06.040 --> 00:01:07.280 seething forces below. 10 00:01:07.640 --> 00:01:13.560 Over hundreds of millions of years during which the surface formed a relatively 11 00:01:13.560 --> 00:01:14.560 thin crust, 12 00:01:14.580 --> 00:01:19.980 the continents and sea beds shifted thousands of miles in response to the upheavals 13 00:01:19.980 --> 00:01:22.220 of the underlying mantle and core. 14 00:01:24.160 --> 00:01:29.540 In one dramatic example of volcanic activity, molten minerals violently forced 15 00:01:29.540 --> 00:01:30.600 their way to the surface, 16 00:01:30.600 --> 00:01:35.880 then cooled and hardened into rock so far a well-known 17 00:01:35.880 --> 00:01:40.420 geological story but then during 18 00:01:40.420 --> 00:01:44.860 further disturbances the hardened rock became fissured later 19 00:01:46.980 --> 00:01:49.500 scientists believe hot mineral 20 00:01:49.500 --> 00:01:54.860 bearing water flowed through the fissures dissolving some of the surrounding rock this 21 00:01:54.860 --> 00:01:59.160 solution crystallized into a network of fibrous veins from 22 00:02:01.750 --> 00:02:04.390 this unusual geological event came a 23 00:02:04.390 --> 00:02:06.230 most unusual mineral. 24 00:02:07.430 --> 00:02:09.910 Even before the dawn of the Iron Age, 25 00:02:10.190 --> 00:02:12.810 it was already proving highly useful to man. 26 00:02:13.950 --> 00:02:17.070 The ancient Greeks, with their well-known curiosity, 27 00:02:17.550 --> 00:02:20.550 investigated it and found its fine fibers 28 00:02:20.550 --> 00:02:23.630 could be spun into yarn, and it resisted fire. 29 00:02:24.890 --> 00:02:29.450 The Greek word for this unique mineral was asbestos. 30 00:02:31.630 --> 00:02:33.690 Today, at Johns-Manville, 31 00:02:33.690 --> 00:02:38.970 we call it asbestos the indispensable mineral 32 00:02:42.400 --> 00:02:46.700 asbestos fibers are flexible and soft yet the 33 00:02:46.700 --> 00:02:52.540 individual strands have greater tensile strength than many types of steel aside 34 00:02:52.540 --> 00:02:53.660 from small amounts 35 00:02:53.660 --> 00:02:58.080 produced in laboratories man has never been able to duplicate its unique 36 00:02:58.080 --> 00:02:59.400 combination of physical 37 00:02:59.400 --> 00:03:04.140 chemical and textile properties in one mineral several 38 00:03:05.960 --> 00:03:08.400 types of asbestos ore are found throughout 39 00:03:08.400 --> 00:03:12.320 the world. Three are commercially important. 40 00:03:13.320 --> 00:03:16.020 Of these, the most useful is 41 00:03:16.020 --> 00:03:21.960 chrysotile. It is found in abundance in Canada in J-M's principal asbestos mine 42 00:03:21.960 --> 00:03:27.900 located at Asbestos Quebec. This huge open pit mine 43 00:03:27.900 --> 00:03:28.900 is one of the world's 44 00:03:28.880 --> 00:03:34.880 largest sources of chrysotile asbestos fiber. It is expected to go on producing 45 00:03:34.880 --> 00:03:40.830 through most of the 21st century. The fiber is processed here at the 46 00:03:40.830 --> 00:03:41.830 world's largest, 47 00:03:41.790 --> 00:03:47.790 most modern asbestos mill. In a little more than 35 years, annual asbestos fiber 48 00:03:47.790 --> 00:03:48.950 production has 49 00:03:48.950 --> 00:03:52.690 been increased from 90,000 to more than 600,000 tons. 50 00:03:54.230 --> 00:03:57.070 A long-term recovery and expansion plan is 51 00:03:57.070 --> 00:04:02.190 in effect to meet the needs of the future. Enlarged facilities will be built at new 52 00:04:02.190 --> 00:04:08.010 locations as the perimeter expands. At present, the open 53 00:04:08.010 --> 00:04:10.510 pit is almost a mile wide and nearly 54 00:04:10.510 --> 00:04:16.170 900 feet deep. Three shifts work around the clock six days a week 55 00:04:16.170 --> 00:04:17.750 to maintain the current 56 00:04:17.750 --> 00:04:24.030 level of production. Ten million tons of asbestos bearing ore mined and processed annually. 57 00:04:24.410 --> 00:04:30.390 In its natural state, chrysotile asbestos 58 00:04:30.390 --> 00:04:34.110 is found in irregular crystalline veins. The 59 00:04:34.110 --> 00:04:38.810 name crude is applied to this cross-vein material before the fibers have been 60 00:04:38.810 --> 00:04:40.010 opened or separated. 61 00:04:41.390 --> 00:04:46.210 Both crude and milled grades are subdivided into groups according to fiber length. 62 00:04:47.770 --> 00:04:52.150 The fibers have a chemical composition similar to the rock in which they are embedded. 63 00:04:52.650 --> 00:04:57.070 This means they cannot be separated chemically as by leaching or electrolysis, 64 00:04:57.250 --> 00:04:59.550 but must be extracted by mechanical means. 65 00:05:00.930 --> 00:05:06.010 The first and biggest step in fiber recovery is removing overburden, 66 00:05:06.130 --> 00:05:08.150 the barren rock, dirt, 67 00:05:08.270 --> 00:05:14.090 and low quality material. In order to expose the underlying ore, more than 68 00:05:14.090 --> 00:05:15.130 three times as much 69 00:05:15.130 --> 00:05:19.130 overburden and waste, 30 million tons, is removed annually. 70 00:05:21.010 --> 00:05:23.210 When the asbestos-bearing rock has been 71 00:05:23.210 --> 00:05:27.930 exposed, it is broken up by drilling and blasting with modern liquid explosives. 72 00:05:39.280 --> 00:05:40.280 Giant power 73 00:05:40.240 --> 00:05:45.500 shovels remove the ore-bearing rock. On the average, a twelve and a half ton bucket 74 00:05:45.500 --> 00:05:49.920 of this ore yields about three-fourths of a ton of usable asbestos fibers. 75 00:05:50.340 --> 00:05:51.340 A 76 00:05:57.180 --> 00:05:58.180 fleet of 77 00:05:57.560 --> 00:06:03.410 giant trucks transports the ore from the pit. The startling change from 78 00:06:03.410 --> 00:06:04.410 this original load 79 00:06:04.310 --> 00:06:09.870 of asbestos-bearing rock to the carefully graded fibers which result later is made possible 80 00:06:09.870 --> 00:06:15.470 through special fiber recovery methods. Here, starting with the rock being dumped, 81 00:06:15.630 --> 00:06:16.630 are some 82 00:06:16.190 --> 00:06:22.000 highlights. First the ore falls down a chute into the jaws 83 00:06:22.000 --> 00:06:23.000 of the primary 84 00:06:29.460 --> 00:06:33.640 crusher. Next it moves to screens and secondary crushers. 85 00:06:34.340 --> 00:06:35.740 The finer fractions 86 00:06:35.740 --> 00:06:41.160 are conveyed to dryers and then to dry rock storage until needed at the mill. 87 00:06:43.400 --> 00:06:47.640 The asbestos-bearing rock is moved on shielded conveyors to the distribution 88 00:06:47.640 --> 00:06:53.090 point at the top of the mill. Inside this massive 14 89 00:06:53.090 --> 00:06:55.550 -story structure the asbestos 90 00:06:55.550 --> 00:07:00.250 fiber is recovered from the ore in a semi- automated operation in a series of 91 00:07:00.250 --> 00:07:01.330 crushing, screening, 92 00:07:01.510 --> 00:07:07.250 and aspirating stages. Asbestos fiber recovery is a 93 00:07:07.250 --> 00:07:10.510 mechanical process. Here is the basic 94 00:07:10.510 --> 00:07:15.890 flow line. After the rock has been crushed to loosen the fibers, 95 00:07:16.070 --> 00:07:17.390 the crushed ore goes 96 00:07:17.390 --> 00:07:22.670 to the primary rock screen. The unseparated ore passes over the screen 97 00:07:22.670 --> 00:07:24.270 as the fines fall 98 00:07:24.270 --> 00:07:30.190 through. The released fibers are sucked up by the aspirator in 99 00:07:30.190 --> 00:07:31.190 a stream of air 100 00:07:30.930 --> 00:07:36.390 moving at 4,000 cubic feet per minute. The fibers are removed from the stream 101 00:07:36.390 --> 00:07:41.670 in the cyclone collector. Here, the clean air stream moves out the top. 102 00:07:42.110 --> 00:07:43.110 The fibers, 103 00:07:43.250 --> 00:07:49.250 losing velocity, move downward. Meanwhile, the screened rock 104 00:07:49.250 --> 00:07:50.610 containing unreleased 105 00:07:50.610 --> 00:07:56.270 fibers is further broken up in the fiberizer. This is a vertical type hammer mill 106 00:07:56.270 --> 00:07:57.730 used to prepare the 107 00:07:57.730 --> 00:07:59.270 ore for further fiber release. 108 00:08:04.020 --> 00:08:07.940 In the fiber cleaning circuit, the paddle trommel screens 109 00:08:07.940 --> 00:08:11.380 out fine grit and de-dusts the fiber in the same operation. 110 00:08:12.020 --> 00:08:14.960 The dust is aspirated away, airborne, 111 00:08:15.220 --> 00:08:21.040 as the fibers fall down to the fiber screen. Here, medium gritty 112 00:08:21.040 --> 00:08:22.340 material and short fibers 113 00:08:22.340 --> 00:08:28.320 are screened out. The longer fibers move on to the Bauer air separator 114 00:08:28.320 --> 00:08:29.940 which further separates 115 00:08:29.940 --> 00:08:35.180 grit from the fibers in a fast-moving stream of air at 8,000 cubic feet per minute. 116 00:08:35.400 --> 00:08:42.900 The cleansed 117 00:08:44.690 --> 00:08:48.030 fibers are again separated from the air stream by cyclone collectors. 118 00:08:48.570 --> 00:08:49.570 Then 119 00:08:55.060 --> 00:08:56.060 they move to the 120 00:08:55.800 --> 00:09:00.940 grader which screens out long or short fibers as required before final mixing. 121 00:09:02.420 --> 00:09:03.440 The overall 122 00:09:03.440 --> 00:09:07.380 asbestos fiber recovery process requires the circulation and filtration 123 00:09:07.380 --> 00:09:12.620 of huge volumes of air for aspirating, cleaning, and de-dusting. 124 00:09:13.740 --> 00:09:18.100 This is accomplished in the huge fan room occupying the upper floor of the mill. 125 00:09:18.620 --> 00:09:23.420 Here, three million cubic feet of air move through the bag filters each minute. 126 00:09:27.250 --> 00:09:31.990 Some or all of the steps in this basic process may be repeated, depending on the 127 00:09:31.990 --> 00:09:32.990 grades to be collected. 128 00:09:32.950 --> 00:09:37.910 The milled asbestos fibers are classified into some 60 standard grades. 129 00:09:38.590 --> 00:09:42.870 Other special grades are processed to meet the needs of particular industries. 130 00:09:46.570 --> 00:09:51.370 This, then, is the basic flow line of the asbestos fiber recovery process. 131 00:09:54.330 --> 00:09:59.850 As the last major component, the mixer helps form an homogenous, consistently 132 00:09:59.850 --> 00:10:01.810 uniform product prior to packing. 133 00:10:06.690 --> 00:10:09.210 The packing operation is also automated. 134 00:10:09.210 --> 00:10:14.530 Packing methods include pressure packing, in which the fiber is accurately weighed, 135 00:10:14.750 --> 00:10:17.010 compressed, and extruded into bags. 136 00:10:19.600 --> 00:10:23.600 The user is assured that each bag shipped will meet specifications. 137 00:10:24.760 --> 00:10:27.360 Bulk shipments are also carefully controlled. 138 00:10:30.620 --> 00:10:34.540 The rigid standards are maintained by continuous quality control. 139 00:10:34.860 --> 00:10:40.600 For example, the Quebec standard screen test is used to determine fiber length and grade. 140 00:10:42.180 --> 00:10:47.940 A 16-ounce sample is subjected to a controlled dry screening in a series of boxes 141 00:10:47.940 --> 00:10:49.240 with successively 142 00:10:49.240 --> 00:10:50.240 finer meshes. 143 00:10:50.780 --> 00:10:55.900 The prepared sample is placed in the top box, then shaken down during a standard 144 00:10:55.900 --> 00:10:56.900 time interval. 145 00:10:59.720 --> 00:11:04.840 After shaking, the amount of each fiber length caught on each screen is measured. 146 00:11:05.440 --> 00:11:10.300 The more long fibers caught on the top screens, the higher the grade of the sample. 147 00:11:16.320 --> 00:11:20.220 The Ro-Tap test is another method of measuring fiber length distribution. 148 00:11:21.100 --> 00:11:26.060 The quantity of fibers retained on each mesh is recorded as a percentage of the 149 00:11:26.060 --> 00:11:27.540 original sample by weight. 150 00:11:27.820 --> 00:11:33.750 A color test may also be used to establish the relative whiteness of a 151 00:11:33.750 --> 00:11:34.750 fiber sample. 152 00:11:34.710 --> 00:11:40.520 The McNett test utilizes a wet screen technique to measure 153 00:11:40.520 --> 00:11:41.540 fiber length distribution. 154 00:11:42.640 --> 00:11:47.020 A weighed sample is washed down through four successively finer screens. 155 00:11:47.020 --> 00:11:52.960 After the water is drained, the fibers retained on each screen are recovered, 156 00:11:53.180 --> 00:11:54.600 dried, and weighed. 157 00:11:55.380 --> 00:11:59.960 The proportional amounts of each fiber length recovered are then expressed as percentages. 158 00:12:02.410 --> 00:12:08.270 The relative surface area of a fiber sample is obtained by the Blaine- Dyckerhoff apparatus. 159 00:12:09.130 --> 00:12:13.110 A predetermined volume of air is automatically drawn through the fibers, 160 00:12:13.330 --> 00:12:16.470 which are loosely tamped into a cell attached to the equipment. 161 00:12:17.130 --> 00:12:22.470 The time required for the air to pass through the sample gives its air permeability 162 00:12:22.470 --> 00:12:23.470 as a basis 163 00:12:23.230 --> 00:12:29.120 for calculating its surface area. The crudy test separates 164 00:12:29.120 --> 00:12:31.640 spicules and bundles of crude fiber 165 00:12:31.640 --> 00:12:37.020 from a milled fiber sample. The well- opened fibers are carried upwards by a 166 00:12:37.020 --> 00:12:38.160 controlled flow of water, 167 00:12:38.300 --> 00:12:43.280 while the unopened fibers remain in the glass cylinder to be dried and weighed. 168 00:12:46.060 --> 00:12:47.120 The strength 169 00:12:47.120 --> 00:12:52.700 unit test evaluates the capacity of a milled asbestos fiber to impart strength 170 00:12:52.700 --> 00:12:57.940 to a steam cured asbestos cement product by breaking test pieces under flexure 171 00:12:57.940 --> 00:13:03.760 as a simply supported beam. The TAPPI 172 00:13:03.760 --> 00:13:05.780 test for drainage is important to the 173 00:13:05.780 --> 00:13:11.460 asbestos cement and asbestos paper industries. A fiber sample is placed in a 174 00:13:11.460 --> 00:13:17.420 test slurry. The mixture is then added 175 00:13:17.420 --> 00:13:19.640 to a column of water and the water is 176 00:13:19.640 --> 00:13:25.560 pumped out. The rate of removal is timed, giving an indication of the drainage characteristics. 177 00:13:28.880 --> 00:13:33.820 The mill houses the fiber development department, which tests and evaluates new 178 00:13:33.820 --> 00:13:34.820 equipment and 179 00:13:34.680 --> 00:13:40.760 milling techniques. To help customers with grade selection and problem solving, sales 180 00:13:40.760 --> 00:13:46.670 service representatives are available throughout the world. At the 181 00:13:46.670 --> 00:13:48.110 J-M Research Center, the 182 00:13:48.110 --> 00:13:53.170 characteristics and uses of asbestos fibers are studied. Facilities include 183 00:13:53.170 --> 00:13:58.870 this apparatus which calculates surface area based on the amount of nitrogen gas 184 00:13:58.870 --> 00:14:03.570 removed from the sample at the extremely low temperatures provided by liquid 185 00:14:03.570 --> 00:14:09.540 nitrogen coolant. This muffle furnace 186 00:14:09.540 --> 00:14:11.360 removes moisture from fibers at 187 00:14:11.360 --> 00:14:16.840 thousands of degrees Fahrenheit. The x-ray 188 00:14:16.840 --> 00:14:19.100 spectrograph is used to measure 189 00:14:19.100 --> 00:14:23.220 traces of other elements found in proportions greater than 1% of a given 190 00:14:23.220 --> 00:14:29.060 an asbestos sample. The apparatus relies on the digital timer, which 191 00:14:29.060 --> 00:14:30.060 gives results at 192 00:14:30.040 --> 00:14:35.590 electronic speeds. The emission spectrograph 193 00:14:35.590 --> 00:14:38.730 is a means of analyzing element traces less 194 00:14:38.730 --> 00:14:43.930 than one percent of a sample. Spectrograph alignment is accurate to within one millionth 195 00:14:43.930 --> 00:14:49.910 of an inch. Other apparatus, such as the electron microscope, 196 00:14:50.150 --> 00:14:51.910 reveal hidden secrets that can 197 00:14:51.910 --> 00:14:54.270 lead to product improvement and new uses. 198 00:14:54.950 --> 00:14:58.930 Here, a typical fiber grade is magnified thousands of times, 199 00:14:59.610 --> 00:15:02.450 clearly showing the strong fibers that 200 00:15:02.450 --> 00:15:03.910 are so effective as a reinforcement 201 00:15:03.910 --> 00:15:05.230 for other materials. 202 00:15:07.650 --> 00:15:09.850 As the needs of modern industry have expanded, 203 00:15:10.570 --> 00:15:13.230 asbestos has appeared in a wide range of applications 204 00:15:13.870 --> 00:15:16.230 suitable to its unique combination of properties. 205 00:15:17.830 --> 00:15:21.310 Long fibers are spun into yarn to lend strength and fire 206 00:15:21.310 --> 00:15:26.980 resistance to textiles asbestos combines easily 207 00:15:26.980 --> 00:15:28.800 with many other materials for 208 00:15:28.800 --> 00:15:34.200 example with cement it is formed and cured to make strong corrosion free pipe 209 00:15:34.200 --> 00:15:39.810 large diameter conduits tap water resources and convey 210 00:15:39.810 --> 00:15:41.290 wastewater the 211 00:15:42.920 --> 00:15:47.220 smaller diameters are installed for such uses as underground irrigation and 212 00:15:47.220 --> 00:15:53.220 sprinkler systems asbestos cement can also be extruded 213 00:15:53.220 --> 00:15:54.840 to form a variety of 214 00:15:54.840 --> 00:16:00.460 shapes it is highly suitable as a building material particularly for architectural siding 215 00:16:03.310 --> 00:16:08.550 asbestos cement shingles are dimensionally stable they provide fire and termite 216 00:16:08.550 --> 00:16:09.850 resistance as well 217 00:16:09.850 --> 00:16:14.430 as strength and beauty for the roofs and siding of quality homes many 218 00:16:16.120 --> 00:16:17.520 of today's caulking compounds 219 00:16:17.520 --> 00:16:23.410 contain asbestos some fiber grades are combined with plastics to 220 00:16:23.410 --> 00:16:24.870 make floor tiles for brighter 221 00:16:24.870 --> 00:16:30.110 interiors. Other J-M fiber grades have been developed for the asphalt industry, 222 00:16:30.390 --> 00:16:35.840 lending strength and bulk to roofing materials. Adding 223 00:16:35.840 --> 00:16:37.480 asbestos to asphalt 224 00:16:37.480 --> 00:16:42.980 paving in airport runways, highways, and bridge decks gives numerous benefits 225 00:16:42.980 --> 00:16:47.680 when a thin overlay of asbestos reinforced resurfacing asphalt is used. 226 00:16:50.060 --> 00:16:53.460 Asbestos is almost irreplaceable in friction materials. 227 00:16:54.180 --> 00:16:55.500 Brake linings in 228 00:16:55.500 --> 00:16:58.040 particular, depend on its strength and heat resistance. 229 00:17:00.140 --> 00:17:03.420 Asbestos reinforcement improves gasket materials. 230 00:17:05.280 --> 00:17:08.000 Asbestos is used to make many grades of paper, 231 00:17:08.200 --> 00:17:10.980 including fine papers for electrical insulation, 232 00:17:11.910 --> 00:17:15.620 protecting large generators, high voltage transformers, 233 00:17:16.310 --> 00:17:18.340 and everyday home appliances. 234 00:17:20.930 --> 00:17:23.580 This special asbestos paper is impregnated 235 00:17:23.580 --> 00:17:24.600 with a phenolic resin. 236 00:17:24.600 --> 00:17:30.980 later the paper is rolled into pipe to form a unique type of pipe used in the petrochemical 237 00:17:30.980 --> 00:17:36.820 industry asbestos is a principal ingredient in a wide variety of 238 00:17:36.820 --> 00:17:38.980 thermal insulating products such 239 00:17:38.980 --> 00:17:42.940 as the pipe insulation on this Arctic tanker because 240 00:17:45.120 --> 00:17:47.140 it is best known for its high resistance 241 00:17:47.140 --> 00:17:52.940 to extreme heat and fire it is hard to imagine modern industry without it new 242 00:17:54.410 --> 00:17:55.470 uses are constantly 243 00:17:55.470 --> 00:18:01.470 being developed. Here an insulation containing asbestos is being applied to 244 00:18:01.470 --> 00:18:05.450 a high-gain antenna for use in outer space. On 245 00:18:17.130 --> 00:18:18.790 the surface of the earth or 246 00:18:18.790 --> 00:18:23.910 voyaging towards a distant planet, asbestos plays a unique role no other 247 00:18:23.910 --> 00:18:29.850 material can equal. As in past ages, so in the future that lies ahead. 248 00:18:30.870 --> 00:18:31.870 Asbestos will 249 00:18:31.670 --> 00:18:36.170 remain the indispensable mineral in the service of mankind.