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Chapter 4 AVAILABILITY, PROCESSING, AND SPECIFICATIONS OF TITANIUM ORE AND TITANIUM TETRACHLORIDE Titanium ore reserves are abundant and widely distributed throughout the world (Figures 7 and 8~. U.S. self-sufficiency in titanium ore has declined from 75 percent in the mid-1960s to 45 percent in 1980 because of the ready availability of low-cost concentrates from other countries rather than from a lack of U.S. reserves. In terms of contained titanium, the manufacture of titanium dioxide (TiO2) in the United States is about 15 times greater than the production of titanium metal. An emergency need for additional raw material for metal manufacture could be met readily by diversion of ore, or of titanium tetrachloride , from the THOU industry. Ore cost, about $0.35 per lb of contained titanium, is a minor part of the price of titanium metal. A potentially large U.S. supply of titanium ore occurs in of f-grade deposits and possibly by-product sources but inadequate technology currently makes their use uneconomical. Development of suitable processes for utilizing such abundant domestic resources could be economically rewarding. Ti tanium Ores A 1972 report of the National Materials Advisory Board Committee on Processes for Rutile Substitutes identified the geologic occurrence, reserves, and principal mines for titanium ores. It discussed the technology for converting the nonrutile ores to rutile-like material for use in manufacturing titanium tetrachloride (TiC14), the basic feed material in preparing titanium metal. TiC14 also is a transitional material in the manufacture of much of the domestic, and the world's, TiO2, which is used mostly in paint pigments and as filler in paint, paper, plastic, and rubber. In substance, the NMAB group concluded that, since the TiO2 manufacturing industry in the United States was about 15 times larger (in terms of contained titanium metal) than the metal production industry, diversion of TiC14 or TiO2 to metal manufacture could be accomplished readily. The group also concluded that deposits of ilmenite ore in the United States and Canada were ample for metal production in the foreseeable future and that research into new methods for preparing rutile substitutes for metal production was not required at that time. The report recognized, however, that only Australian concentrate then was being used in the U.S. production of sponge. (It remains the major source material in 1981.) 23

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24 it_ Wr-1 ~ 1 ~ 3 - ~IF,_, h I', =_ _, ; . A__ __ ., ~ ~ , 1 t~.~.= ~ f_,~., ~-- ~ i L41 I, . - __ _= - 1 -'' ' ' 1 I.-. ~ A. _ _ :_ ~S ~2 / arm.], ;,., .) Figure 7 Location of important titanium ore bodies in the Uni ted States . Source: DoD Metals ant Ceramics Information Center 1981.

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25 - i:D me . ~: ,.~ see 71 ~ - _: o err 037~- ~-~ ~,3 Figure ~ Location of important titanium ore bodies. Source: DoD Metals and Ceramics Information Center 1981.

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26 The remainder of this section summarizes and brings up to date the findings about titanium ore supply and ore processing contained in the 1972 NMAB report. Unless otherwise identified, data for this chapter were drawn mainly from the U.S. Bureau of Mines Minerals Yearbook 1978-1979 and 1980. Current Ore Supply The major change in the titanium ore situation since the 1972 NMAB report was written has been a large increase in the manufacture, both domestically and abroad, of rutile substitute from ilmenite. However, the following visible changes could have a significant impact on the titanium ore supply in the future: 1. Production of natural rutile has declined in the United States, has leveled off in Australia, and has increased in South Africa and Sierra Leone. Small-scale production of rutile has started in Sri Lanka (Ceylon) at the rate of 14,000 tons per year (tpy), large-scale production of rutile has resumed in Sierra Leone with a target of 110,000 tpy, and large-scale production of high titania slag from ilmenite has started in South Africa (about 400,000 spy). 2. Florida reserves of beach sands, which are the source of the ilmenite-leucoxene-rutile concentrate used by the major U.S. manufacturer of TiO2 via the TiC14 route, have continued to shrink. New potential by-product sources of titanium have emerged. These include recovery of accessory minerals from Athabasca (Canadian) tar sands, recovery of TiC14 or TiO2 from possible future chlorination of bauxite or clay in the preparation of aluminum chloride f or the Alcoa aluminum chloride system now in a demonstration-plant phase, recovery of rutile from porphyry copper ores, and recovery of ilmenite from the tails of a sand-clay operation in California. Additional drilling and laboratory testing of samples has been done to delineate the potential of a perovs kite (calcium titanate) ore body in Colorado that appears to contain about 400 million tons of material at a grade of 12 percent TiO2. U.S. dependence on foreign titanium ores has been increasing and imports now account for about 55 percent of consumption. In view of the long lead times (commonly from S to 15 years) needed to bring a new ore source or technology into production, the current panel believes it prudent to identify factors and developments in ore supply that may influence the future availability of titanium ores to U.S. industry. To present these findings in proper context, ore occurrence, resources, and

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27 production operations and data are summarized; trends and developments that may have a bearing on future ore and related metal supply are identified; and ore processing to TiC14 or TiO2 and production statistics from concentrate to metal are presented. (The technology of alternative routes for manufacturing titanium metal from TiC14 or ether intermediate materials is discussed in Chapter 5.) Ore Occurrence Commercial ores contain titanium in the forms of ilmenite (FeTiO3 with S2.7 percent TiO2), altered ilmenite (with up to about 65 percent TiO2), leucoxene (highly altered ilmenite with up to about 90 percent TiO2), and rutile (TiO2~. Anatase, another crystal form of TiO2, is soon to become a commercial source material. Commonly occurring noncommercial minerals are perovskite (CaTiO3 with 58.9 percent TiO2) and sphene (CaTiSiOs with 40.8 percent TiO2~. Resources and Concentrate Production As c lassified by the U. S . Bureau of Mines and the U. S . Geological Survey (1980), "reserves" are deposits capable of yielding economic concentrates under current economic conditions with present technology. "Other resources" are those deposits containing titanium minerals in such form and grade as to be reasonably considered a source of titanium for the future. About 29 million tons of U.S. resources are in a Gunnison County, Colorado perovskite deposit for which suitable processing technology still has to be demonstrated. By-product sources of titanium concentrate, currently of small consequence, could make important contributions to production if suitable technology can be developed. Mining and processing technology for conventional ilmenite and rutile deposits have changed little in recent years except for the techniques of making artificial rutile that are still being modified. Reserves and Resources World ilmenite and rutile reserves (Figure 8) and producing countries as of 1979 are identified in Appendix E (Tables E-1 and E-2). U.S. reserves and resources (Figure 7) also are listed by state in Appendix E (Table E-3). It has been estimated that U.S. reserves of 17 million tons of titanium in ilmenite and 1 million tons in rutile are sufficient to meet U.S. d~mands to 2000. If imported concentrates continue to provide about

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28 5 5 percent of U. S . titanium consumption, the U. S. reserves will last much longer. Total estimated world reserves of 301 million tons of titanium are over four times the estimated 1978 to 2000 world demand of 64 million tons. The demand for titanium metal is only about 7 percent of total titanium demand; therefore, it is not likely to cause any rapid depletion of reserves . On the contrary, stocks of ilmenite and rutile maintained for pigment manufacture could provide an emergency supply of f eed material for metal production. World titanium capacity and production for 1978 are displayed in Table 1 f or concentrates of ilmenite, rutile, synthetic rutile, sponge, and titans pigment. U.S. production of ilmenmite and rutile concentrate peaked at about 32S,000 tons of contained titanium in the mid-1960s. Only about 70 percent as much titanium in concentrate has been produced annually since 1971. As noted in the introduction to this chapter, this is due to economics and the ready availability of foreign ores and not to any lack of domestic reserves. Outside of the United States, the reserves in Canada, Finland, Norway and most of those in the USSR are in hard-rock deposits of ilmenite-hematite and ilmenite-magnetite. The remainder of the world's reserves are almost entirely in beach-sand deposits. U.S. reserves are about 40 percent in the hard-rock iLmenite in New York and 60 percent in beach-sand deposits. Concentrates from the beach sands, but not from the New York ilmenite, are amenable to direct chlorination for TiC14 production. However, only one company, a pigment manufacturer, has been using ilmenite as a direct chlorination feed material. Those titaniferous magnetite deposits for which suitable processing technology has not been demonstrated are included in the resources columns in Table 1. Frequently, the complexity of the mineral assemblage and the degree of interlocking in these deposits does not permit ready preparation of marketable concentrates by conventional beneficiation techniques. Illustrative of this type of deposit are the titaniferous magnetites in Minnesota and Wyoming. Neither economics nor shortages of re serves have been sufficient to stimulate the massive research needed to develop methods for recovering titanium from such lower grade resources. Past and current efforts on such domestic resources, motivated by shifting views of the desirability for U.S. self-sufficiency in critical materials, have been mostly of a desultory nature. Recent research is reviewed below. Hardrock Ilmenite Depo sits Conventional open-pit mining is used at three of the world's ilmenite rock deposits--Allard Lake, Canada; Tahawns, New York; and Tellnes, Norway. Underground mining is used at Otanmaki, Finland. Except for Allard Lake ore, crushing and grinding is followed by combinations of gravity, magnetic, and flotation techniques to produce concentrates of 45 to 47 percent TiO2. Allard Lake ore at 32 to 36 percent TiO2 is concentrated

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29 TABLE 1. World Titanium Capacity sud Production, 1978 (in short tons t$tanlum content) Ilmeni te Rutile - Ruti le Synthetic Caps- Capa- Capa city Prod ' n city Prod 'n city Prod 'n Sponge Plgment Capa- Capa city Prod 'n city Prod ' n No rth Ameri ca Unitee ~tates 31s 218 1" ~60 1(3 23 16 ~523 420 Canada 525 399 - - - - - - 64 NA Mexico _ _ _ _ _ ~ _ _ 22 NA Sotal 843 617 14 W 60 10 23 18a 609 NA South America, Brazil 8 7 (b) (~) - _ _ _ 22 NA Europe Finland 51 3 9 - - - - - - 5 3 NA France - - - - - - - - 94 NA Germany, Fet. Rep. - - - - - - - - 212 NA Norway 280 228 - - - - - - 17 NA United Kingdom - - - - - - 3 2 16S 136 Soviet Union 124 121 7 6 - _ 42 39 82 NA Other _ _ _ _ - _ _ _ 195 NA , 7 6 - - 45 41 818 NA Total 455 288 Africa, South Africa, Rep. of, and Asia 112 51 India 80 58 3apan ( b) ( b) Malaysia 75 67 S2~t Lanka 35 13 Taiwan Other 35 11 - - - - 18 NA 5 3 17 NA - - 8 NA - - 32 25 13 10 143 113 3 4 - - _ _ 8 ? - - - - _ _ - - 17 NA - - 3 NA - - _ _ _ _ 20 NA lotal 190 138 13 10 100 25 13 10175NA NORLD TOTAL 2,148 1, 666 294 188 195 6S 81 691, 6841, 400 NA - Not available a - Calculatet: Productlon - consumptlon - imports ~ stock changes. ( b) - Less than one-half unit. Source: Mlneral Facts and Problems, U.S. Bureau of Mines 1980.

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30 by gravity methods and the concentrate is roasted to eliminate sulfur and then smelted with coke in an electric furnace. Most of the iron is selectively reduced to a marketable pig iron. The titanium goes into the slag with ~ 70 to 72 percent TiO2 content that, because of its low iron content, is a preferred feed for manufacturing TiO2 pigment by the sulfation route. Conversely, because the slag contains MgO (5 percent) and CaO (l percent), which form troublesome sticky phases when chlorinated, the slag is considered undesirable for direct chlorination to TiC14. BecaXrSand Deposits Mining of fossil beach sand containing ilmenite, leucoxene, and rutile is accomplished by dredges or draglines, usually the former. Heavy minerals initially are separated from the quartz-feldspar-mica fraction of the sand using spirals or cones. Jigs sometimes are used on stream type placers that contain a large range of particle sizes. The heavy sands are dried and an ilmenite-rutile fraction is made on electrostatic equipment. The titanium minerals then may be further separated into an ilmenite-leucoxene fraction and a rutile fraction removed by high-intensity magnetic equipment. Depending on the degree of ilmenite alteration, ilmenite (and leucoxene) concentrates from beach sand have TiO2 contents ranging from 45 to 50 percent, the same as in rock ilmenites and in the South African sand ilmenite; f ram 54 to 70 percent in Australian, Indian, and U.S. altered ilmenites; and from 70 to 90 percent in Australian leucoxene. Perovskite Deposits The perovskite deposit In Gunnison County, Colorado, reported to contain lOO million tons of 12 percent TiO2 measured ore and 400 million tons of 12 percent TiO2 indicated and inferred ore, is close to the surface and presumably mineable by open pit methods (Thompson and Watson 1977~. Results of beneficiation testing have not been released. Laboratory tests to prepare titanium carbide from a sample of perovskite concentrate have been conducted by the U.S. Bureau of Mines (Elger et al. 1980~. However, prolonged fusion in an electric furnace to form TiC4 and calcium carbides is inordinately expensive in terms of e quipment and power requirements. Thus, this technology is not promising as an economical route to utilizing pervoskite concentrate. Potential By-product Sources of Titanium Concentrate Recovery of ilmenite from tin dredging in Malaysia is the only current by-product production of titanium minerals. Other potential sources are the "red mud" wastes from processing bauxite ore for alumina

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31 and from a conceptual process for chlorinating bauxite to prepare AlC13 for electowinning of aluminum; porphyry copper mill tailings; sand and gravel, gold placer, and silica-c lay operations; and tar sands operations. Of these, Canadian tar sands and waste tails from a silica-clay operation in California offer the best prospects for by-product titanium in the next several years should the need for alternative sources arise. Po ssible recovery of titanium f ram red muds containing 4 to 11 percent TiO2 was discussed in the 1972 NUMB report . About 300,000 to 4 00, 000 tons of TiO2 are contained in the muds discarded each year in the United States. Technology for economic recovery of the titanium they contain has yet to be developed and demonstrated. Bauxite ores contain 1 to 6 percent TiO2. If electrowinning of aluminum by the chloride route, as is now being tested by Alcoa, becomes commercial and if direct chlorination of bauxite becomes the established route for preparing the aluminum cell feed, the by-product recovery of TiC14 from chlorinating bauxite or clay to make AlC13 with recovery of TiO2 or TiC14 would be likely. A process developed by the Toth Aluminum Corporation for chlorinating bauxite or clay with recovery of TiC14 or TiO2 has been described (U.S. Environmental Protection Agency 1976~. Most of the porphyry copper ores contain 0.3 to 0.75 percent TiO2, largely as rutile. Essentially all of the contained TiO2 is found in the finely ground mill tailings that are discarded after the copper and molybdenum are selectively floated. Laboratory research to recover the rutile was done on a sample of tailings from Arizona containing 0.75 percent TiO2 (Llewellyn and Sullivan 1980). By a complicated procedure involving desl iming, flotation and rejection of sulfides and carbonates, acidulation, and flotation and cleaning of rutile concentrate, about 37 percent of the TiO2 was recovered in a concentrate of 35 percent TiO2 grade. This recovery of 5 to 6 lbs of rutile in a low-grade product from a ton of originally alkaline tailings would fall far short of paying the operating costs. With present technology, the outlook is dim for by-product titanium from copper tailings. Possible recovery of titanium concentrate from West Coast sand and gravel operations and gold placers recently was investigated by the U.S. Bureau of Hines (Gomes et al. 1979 and 1980; Martinez et al. 1981~. Results of laboratory tests are reviewed in Appendix E. A silica-clay operation in California that has tailings containing about 20 percent TiO2 may have the potential for titanium by-product recovery. Syncrude Canada, Ltd., operates an Athabaska tar sands plant for recovery of a scheduled 105,000 barrels of oil per day from tar sands containing 9 to 16 percent bitumen. A hot water extraction process is used. After extraction and discard of the primary tails, bitumen is diluted with naptha and centrifuged to remove entrained solids, which

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32 also are discarded. These centrifuge tailings have been found to contain about 7 percent TiO2 representing a recovery of about 85 percent of the TiO2 in the tar sands feed. In laboratory tests, the entrained bitumen was burned off and the oil-free sands were treated on spirals and electrostatic and magnetic equipment to make a product grade of about 69 percent TiO2 . The concentrate was observed to be highly weathered and tests indicated that separation could be made of ilmenite, leucoxene, and rutile concentrates. A possible annual production of 85,000 tons of titanium concentrate from the Syncrude plant was projected. This might be doubled if the centrifuge tails f ram the nearby Suncor tar sands plants were combined with the Syncrude centrifuge tails for treatment. Market and economic studies are being made by Syncrude to determine the feasibility of titanium minerals production (Trevory and Shuttle 1981~. Information about the titanium minerals potential of Utah tar sands is, as yet, lacking . Synthetic Rutile Titanium tetrachloride, for the manufacture of titanium metal or titanic pigment, historically has been made in the United States by chlorination of rutile concentrate of about 96 percent TiO2 grade. Increasing world demand and shrinking reserves caused a steep escalation of rutile concentrate prices that resulted in the development of processes and the construction of plants for converting ilmenite concentrate to synthetic rutile. Although ilmenite concentrate and slags made f ram ilmenite can be chlorinated directly, high operating, purification, and waste disposal costs in U.S. practice favor preliminary upgrading of the chlorinator feed material to rutile substitutes. Various processes for upgrading ilmenite concentrate were reviewed in the 1972 XMAB report. Those in use all involve a reductive roast, an acid leach, or artificial accelerated weathering. Frequently, an oxidizing roast is employed to convert extracted impurities back to the oxide with recovery of the hydrochloric acid used in leaching. All these processes pose the possibility of more or less severe environmental and waste disposal problems and costs, depending on the location, f eed material, and process used. Curre nt Prac Lice Commercial plants in India, Japan, Malaysia, Taiwan, and the United States are designed to partially reduce the iron in the ilmenite and then remove much of the iron along with part of the magnesium and calcium by leaching with acid. One plant in Australia reduces the iron to the metallic state and then re-oxidizes it irr a water slurry for its removal as a hydrated oxide.

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33 Kerr-McGee at Mobile, Alabama, makes synthetic rutile for use in its titanium pigment plant at Hamilton, Mississippi, and for sale. Ilmenite concentrate at a grade of about S9 percent TiO2 from Australia is the feed to the upgrading plant. Production was at a rate of 80,000 to 85,000 tpy in mid-1981 and was scheduled for 110,000 tpy in 1982. Slag of 85 percent TiO2 grade made f rom Richards Bay, South Africa, sand concentrate is low enough in magnesium, calcium, and manganese to be considered as a rutile substitute suitable for direct chlorination. U.S. imports of South African slag, another rutile substitute, were 30,000 tons in 1979 and 50,000 tons in 1980. Major U.S. imports of synthetic rutile in 1980 were 61,000 tons from Australia, 10,000 tons from India, and 7, 000 tons f rom Japan. S1 ag Benef ice ation Research Laboratory work on benef iciating titanium slags that are too impure for direct chlorination is being done by the U.S. Bureau of Mines (Elger et al. 1981~. The slag, made from domestic ilmenite, is sulfa/ion-roasted and then leached to remove solubilized calcium, magnesium, and manganese. Early data show that most of the calc ium and manganese and 70 percent of the magnesium were removed from the slag. The process is in an early stage of development and is not ready for assessment . TiO2 Pigment and TiC14 TiO2 pigment, a highly purif fed f arm of rutile or ana~case, is prepared by processes involving the sulfuric acid digestion or the chlorination of titanium dioxide concentrates. TiC14 that is of adequate purity to yield pigment TiO2 ordinarily must be further purified to be suitable for the manufacture of titanium metal sponge by any of the three commercial routes--magnesium, sodium, or electrolytic reduction. TiO2 pigment, when mixed with carbon, is readily chlorinated to make TiC14 suitable for reduction to metal, but this is not done commercially. U.S. pigment production was 700,000 tons in 1978 and 714,000 tons in 1980. (Production and purchasing specifications for TiC14 offered or desired by several U.S. firms and by the Soviet Union are included in Appendix F. World capacity and production of pigment for 1978 is shown in Table E-1 of Appendix E. TiO2 Via Sulfuric Acid Digestion Ilmeni te concentrate or titanium slag is digested in sulf uric ac id . Any Fe+3 present is then reduced to Fe+2 by addition of scrap iron; part of the ferrous sulfate is crystallized and removed; the titanium hydroxide i s precipitated by hydrolysi s, f iltered, and f inally calcined to the oxide. The process is tolerant of low-grade and impure feed material except that excessive chromium, phosphorous, niobium, manganese,

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34 and vanadium degrade the pure white color of the pigment. suffers from a difficult and costly sulfate-waste disposal existing U.S. plants using the sulfate process are capable 250,000 tons of pigment per year. TiO2 Via TiC14 The process problem. The four of manufacturing U.S. practice for making TiO2 for pigment involves the chlorination of ru tile or synthetic rutile concentrate in the presence of petroleum coke in fluid-bed reactors at 850 to 950C. Iron, aluminum, and silicon oxides also react to form volatile chlorides. These and other impurities that form volatile chlorides are separated from the TiC14 by fractional distillation. Vanadium is removed from liquid TiCl4 by adding copper to form a precipitate of copper vanadyl chloride. Purified TiC14 vapor then is burned with air or oxygen under controlled conditions and with selected additives to make TiO2 of the required particle size and form. The process is intolerant of more than minimal magnesium, calcium, or manganese in the feed. These form troublesome liquid phases in the chlorinator that cause plugging dif f iculties on cooling when they leave the reactor. Environmental and waste disposal factors are considered less troublesome when using suitable lo~impurity feed. The nine existing U.S. plants using the chlorination process are capable of manufacturing about 800,000 tons of pigment per year. Price Comparison of Titanium Materials Table 2 indicates that the ore cost of titanium, even of its most expensive form (natural rutile), is a minor part of the sponge price. TABLE 2 Price Comparison of Titanium Materials Commodity Median Price of contained Price Ti (~/lb) . Ilmenite, long ton, 54 percent TiO2, fob Atlantic portsa $65-70 lo Slag, long ton, 70 percent TiO2, fob Quebec, Canada a 6135 14 Slag, long ton, 85 percent Ti02, fob South Africat $170-180 15 Synthetic Rutile, 93.5 percent TiO2, st, fob Mobile, Ark $340 30 Rutile (natural), short ton 96 percent Ti02, fob Atlantic and Great Lakes Portia Pigment, lb, rutile, TiO2 c Sponge, lb, 99.3 percent Ti, max. 115 Brinell a Sponge, lb, Japanese, 99.8 percent Ti, 97-99 Brinelll Titanium tetrachloride, lbC a Engineering & Mining Journal, June 1, l9X1. b U.S. Bureau of Mines 1981. c Chemical Marketing Reporter 1981. $450-475 40 $0.69 115 $7.22 727 $8.85-10.03 946 $0.35 40

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35 Appraisal of Exploration, Mining, and Concentrating Technology Theories of titanium ore deposition and criteria for finding titanium deposits have been developed and discussed (Force 1978). Well-established techniques for surface and underground mining exist and are readily modified for local conditions and variations in ore occurrence. Similarly, beneficiation practices have the flexibility to handle widely different assemblages of titanium and accessory minerals in beach-sand deposits. Massive ilmenite-magnetite deposits are amenable to physical beneficiation using conventional gravity, flotation, and magnetic procedures provided that discrete mineral particles can be liberated without excessively fine grinding. A combination of physical beneficiation and smelting has proved applicable to the massive ilmenite-hematite deposits at Allard Lake, Canada. Overall, the relatively low prices of $0.10 to $0.15 per lb of titanium in ilmenite and slag concentrate and of $0.27 to $0.40 per lb of titanium in synthetic and natural rutile concentrate indicate the efficacy of ore finding, mining, and concentrating practices. Ilmenite-magnetite ores of suitable grade that are not amenable to beneficiation by physical means may be smelted to produce titanium slag and pig iron. However, practicable technology is lacking for utilization of lower grade ilmenite-magnetite ores with tightly locked mineral components, (e.g., those from the Iron Mountain deposit in Wyoming). Plausible new ideas are needed to justify additional research to f ind feasible extraction processes for such ores. Combinations of pyrometallurgical and hydrometallurgical techniques to prepare synthetic rutile from ilmenite concentrate have been in commercial use for several years. As operating experience is gained, the expected incremental improvements should lessen the potentially severe environmental and waste-disposal problems. Innovative research for direct preparation of TiC14 from ilmenite concentrate and slag produced from domestic ilmenite-magnetite deposits seems worth pursuing. The direct chlorination of ilmenite to TiCl4 and FeC13 followed by fluidized-bed conversion of the separated FeC13 to C12 for recycling and the resulting Felon for market has been proposed (Paige et al. 1975~. The technique was operable in the laboratory, but apparent scale-up difficulties have discouraged commercial adoption. Concentrate has been prepared in the laboratory from Colorado perovskite ore by physical beneficiation, but feasible technology for utilizing the concentrate is lacking and requires development. A comprehensive investigation by Syncrude Canada, Ltd., has established a potential for economic by-product recovery of titanium concentrate from Athabasca tar sands. In assessing possible by-product sources of domestic titanium, it would be of interest to know the extent of available titanium in Utah tar sands.

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36 Utilization of the large by-product titanium potential of Bayer plant (aluminum production) red mud and porphyry copper tails requires cheaper and more effective technologies than now exist. The possibility of recovering by-product TiC14 f rom chlorination of bauxite or clay in the aluminum industry depends on the direction taken in the future development of the Alcoa chloride process. Other potential by-product sources (e.g., those revealed in the recent U .S . Bureau of Mines surveys of sand, gravel, and clay plant waste s) appear to have merit for exploitation with the use of conventional technology. These could become a source of titanium minerals provided the individual sources are of suf f icient tonnage and grade to permit an economical operation. Specifications for Minerals and Mineral Concentrates Rutile Concentrates of the naturally occurring mineral rutile (TiO2) are the historically preferred raw material for titanium metal production through the intermediate product, titanium tetrachloride. Rutile concentrates may be chlorinated in the presence of a Deduct ant (e.g. petroleum coke), commonly in fluidized-bed reaction vessels, to produce the tetrachloride. To satisfy the requirements of operation of the various modifications of reduction-reaction equipment, rutile may be purchased to specifications that limit particle size and impurity composition produced by private companies. The U. S. National Stockpile Purchase Specification P-49-R6, part of which is included in Appendix G. covers rutile that is satisfactory for use in the production of titanic metal (via the tetrachloride intermediate product), welding rod coatings, and f erro-t itanium alloys. Synthetic Rutile No public specifications cover the products, generally known as synthetic rutiles, that result from the upgrading of mineral concentrate s such as ilmenite and leucoxene by physical and thermal-chemical processing. The synthetic rutiles may be used in the production of t itanium tetrachloride f or conver Sian to metal or othe r produc ts . There are several processes in use for the production of synthetic rutile and each aims at achieving a 90 to 95 percent TiO2 content while minimizing iron, calcium, magnesium, and other impurities. Further, physical properties such as particle size are controlled to within acceptable limits. The chemical and physical characteristics acceptable to purchasers are described in purchasing agreements.

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37 Slags from Ilmenite Products that are reasonably high in titanium dioxide (e.g., 70 to 90 percent) can be produced from ilmenite by smelting to reduce the iron oxide content to metal leaving the titanium in the slag as oxide. The slags may contain as much as 5 to 10 percent residual iron that can be chlorinated readily, but this reduces chlorinator throughput in terms of the desired titanium tetrachloride output and also results in a problem regarding the disposal of the iron chlorides produced. Nevertheless, slags may be used in the production of titanium tetrachloride when their availability and economics offer advantages to the producer. There are no public specifications covering slags produced from ilmenite-type concentrates that are useful in manufacturing titanium tetrachloride. However, it is well-recognized that slags for chlorination must be low in calcium, magnesium, and manganese. Ilmenite Concentrates There are no public specifications for ilmenite concentrates suitable for use in chlorinators for the production of titanium tetrachloride. In the United States, E. I. du Pont de Nemours ~ Company, Incorporated operates mining, concentrating, and chlorinating equipment that utilizes ilmenite concentrates enriched with leucoxene and rutile fractions as feed stock. The titanium tetrachloride product is used primarily in the production of titanium dioxide f or pigment, welding rod coatings, and other uses, but with suitable upgrading by additional distillation, the tetrachloride produced could be used in the production of titanium sponge metal. Specifications Covering Titanium Tetrachloride Specifications generated by private companies for the purchase of titanium tetrachloride can be proprietary and therefore not publicly available . An example of a purchasing specif ication, not held as proprietary, is given in Appendix F. Producer specifications for titanium tetrachloride of United States (Cabot Corporation) and Soviet manufacture also are given in Appendix F. No public specifications exist. None of the specification information available from U.S. producers and users of titan) um tetrachloride f or metal production includes the important data relating to the metal-oxychloride and dissolved gases contents. In this respect, the Soviet specification is informative. It shows that the oxygen content in the form of oxychlorides, carbon compounds, and chlorine and chlorine compounds, other than the titanium tetrachloride, can be significant. The control of these impurities to low levels is as important as the control of the metallic impurities to the product) on of high-quality sponge titanic. It has been stated that an additional purification step (e.g., additional distillation) is capable of

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38 rendering a pigment-grade tetrachloride (e.g., the product described by du Pont ~ suitable for the production of metal . A low oxygen content and a reduction of other impurities in titanium tetrachloride are requirements for the production of good-quality sponge titanium metal.

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39 REFERENCES Dean, R. S., and B. Silkes, 1946. Metallic Titanium and Its Alloys. Information Circular 7381. Washington, D.C.: U.S. Bureau of Mines. De an , R . S ., J . ~ . Long, F . S . Wartman , and E . R . Ander son , 1946 . Preparation and Properties of Ductile Titanium, Mineral and Metallurgical Engi peering Technological Publication No. 1961. Dean, R. S., F. S. Wartman and E. T. Hayes, AIME Transactions, Vol. 166, 369-381. 1946. Ductile Titanium: Its Fabrication and Physical Properties, Technical Publication No. 1965. AIME Transactions, Vo1. 166, 381-389. Elger, G. W., W. L. Hunter, and E. Mauser. 1980. Preparation and Chlorination of Titanium Carbide from Domestic Titaniferous Ores. Report of Investigation RI 849 7 . Washington, D.C.: U.S. Bureau of Mines . Elger, G. W., J. E. Tress, R. R. Jordan, and L. L. Oden. April 1981. Ugrading domestic titaniferous resources for producing titanium. Paper presented at Pacific Northwest Metals and Minerals Conference, Portland, Oregon,. Force, E. R. Some predictive techniques in heavy mineral exploration. 1979. Paper presented at the Society of Manufacturing Engineers (SHE), American Institute of Mechanical Engineers (ADME) Fall Meeting, Orlando, Florida, September 11-13, 1978. Gomes, J. M., G. M. Martinez and M. M. Wong. 1979. Recovering By-product Heavy Minerals from Sand and Gravel, Placer Gold, and Industrial Mineral Operations. Report of Investigation 8366. Washington, D . C .: U . S. . Bureau of Mines . Gomes, J. M., G. M. Martinez and M. M. Wong. 1980. Recovery of By-product Heavy Minerals from Sand and Gravel Operations in Central and Southern California. Report of Investigation 8471. Washington, D.C. : U.S. Bureau of Mines. Llewllyn, T. O., and G. V. Sullivan. 1980. Recovery of Rutile from a Prophery Copper Tailings Sample. Report of Investigation 8462. Washington, D.C.: U.S. Bureau of Mines. Martinez, G. M. , J. M. Gomes and M. M. Wong. 1981. Recovery of By-product Heavy Minerals from Sand and Gravel Operations in Oregon and Washington. Report of Investigation 8563. Washington, D.C.: U. S. Bureau of Mines.

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40 National Materials Advisory Board Committee on Processes for Rutile Substitutes. 1972. Report NMAB-293 Processes for Rutile Substitutes. Washington, D.C.: National Academy of Sciences. Paige, J. I., G. 8. Robidart, H. M. Harris and T. T. Campbell. 1975. Recovery of chlorine and iron oxide from ferric chloride. JOM, Vol. 28, 12-16. Thompson, J. V., and D. L. Watson. 1977. Appraising large diameter core and percussion drilling for bulk samples. E&NJ Vol. 178 :80-82. Trevory, L. W., and R. Shuttle. 1981. A New Source of Heavy Minerals from Canadian Oil Sands Mining Operation. Manufacturing Engineering, S ME; Preprint 81-20, Dearborn, Michigan. U.S. Bureau of Mines. 1978-79 and 1980. Minerals Yearbook. Vol. 1, Metals and Minerals, Titanium. U.S. Government Printing Office, Washington, D . C. U.S. Bureau of Mines and U.S. Geological Survey 1980. Principles of a Resource/Reserve Classification for Minerals. USGS Circular 831. U.S. Government Printing Office 1980. U.S. Environmental Protection Agency . 197 6. Environmental Considerations of Selected Energy-Conserving Manufacturing Process Options. Report EPA-600/7-76-034h, Vol. 8, Washington, D.C.: U.S. Environmental Protection Agency.