*4 4V MM SCIENCE Li 3RpRY UMI. r " Y ! a .fie! :- . ' O.F l©plRrr o s . 1817 A R T E S SCIENT'i A V R I TAS TITANIUM A Suwiry of the Literature Presented as a Thesis in Economic Geology by Charles D. Campbell )*15 Qm---- i9 3 4- TABLE OF CONTENTS Introduction ... O.........................O.."....1. Purpose of the Paper Chemical Properties of Titanium Nine ral1ogy and Petrography ......... ............. 3. Origin O..........O..OS........ 5. ~........oo. 4. Distribution Domestic .................................. 5. Foreign NothAmerica ........... 0ee~.. .. 5..13 Central America *..."o."..."."""""""."14. South America ... "...000........""""... 15. Asia *..O..O.................:.......15. Af'rica .........................SSSO 17. Oceania """"""""""""".""""""S""""""..".S18. Europe """""..""".""."""19. mining and Concentration ".""""""""""""""."""""" .20. Uses of Titaniam S....................OOOO.....22. Bibliograpy.......SS@ ... ..................... 25. Introduction There has been, of late years, a growing demand for titanium in various forms for use in the paint industry, in metal making, in dyeing, pottery manufacture, and as an incandescent medium. For this reason, the problems of its occurrence in nature, its mining, and its preparation for use, have received some attention in the form of numerous articles and monographs. In this paper, I wish to give a summary of the more prominent of these writings, with spe- cial emphasis on the geologic phases of them. Titanium is generally classed with the rare elem- ents, although it is the ninth element in abundance on the lithosphere. In analyses of 800 igneous rocks, carried out in the laboratories of the United States Geological Survey, all but sixteen contained titanium. Because it was found in the dust of the Mt. Pelee explosion, it is assumed to be pre- sent at depth in the earth. From the soil, titanium makes its way into certain plants, and its traces are present in peat and some coals. The spectra of the sun and other stars show titanium lines. The chemical relations of titanium with other elem- ents of Group IV of the periodic table is shown below: Group IV. 0 12.000 Si. 28.06 Ti 48.1 Go 72.60 Sr 91. - Sn 118.70 178.6 Pb 207.20 Th 232.15 2 The pure element is difficult to make. It is iso- morphous in crystal form with silicon and zirconium, and is a brittle and very hard gray metal. If heated in air over 1200 0., titanium oombines with oxygen and nitrogen to form oxide and nitride. It burns in oxygen at 6100, and in nitrogen at 8000. In blast furnaoes, the troublesome red compound of uncertain composition, titanium oyanonitride, is formed by a reaction between Ti02 , carbon, and nitrogen. Titanium also burns in chlorine at 350°0., and with bromine and iodine at higher temperatures, forming halides of the TiXi type. Its silicide (TiSi) and boride (TiB) are nearly as hard as diamond. The reactions with acids are variable. Hot dilute hydrochloric or sulphuric acids yield hydrogen and trivalent salt, while titanic acid and metatitanic acid are the respective products of reaction with dilute and concentrated nitric acid. Titanium forms alloys with many metals, but the most valuale are with iron, copper, manganese, nickel, and cobalt. 3 Mineralogy and petrology. W. K. Thornton lists fifty titanium minerals and ten minerals which may contain titanium in varying amounts, but of these only rutile (Tio 2), ilmenite (FeTiO 3), and titaniferous iron ore are commercially important. In the case of titaniferous magnetite, microscopic examination may or may not show ilmenite intergrown with mag- netite. Where such intergrowth shows, the ilmenite lies along the directions of octahedral cleavage in the magnetite. Where such is not evident, Singewald says that the ilmenite is in solid homogeneous solution with the magnetite. However, F. F. Osborne takes exception to this view, and suggests that the intergrowth is too fine to be observed. According to him, the titaniferous magnetite of the Adirondacks and Canada was at high temperatures a homogeneous solution, but that falling of temperature caused a supersaturation of the ilmenite so that it separated out well above 5004 C. In localities where hematite is the iron oxide Inter- grown with ilmenite the former occurs as discs parallel to the basal parting of the ilmenite. The occurrence of hematite rather than magnetite is attributed to the exhaustion df FeO in forming ilmenite and the associated ortho--and metasilioates. The rarity of rutile (the pure titanium oxide) seems to show that here at least it has a strong affinity for ferrous oxide. Ilmenite is also found in pegmatites, evidently a late segregation mineral. In Virginia and Southern Norway, rutile and apatite, or ilmenite and apatite occur together in dikes cutting less basic igneous rock. Such ultrabasic dike rocks are called "nelsonites", from Nelson County, Virginia, where they occur. Ilmenite and rutile are found in contact and reg- gional metamorphic rocks. The ilmenite of the great Travancore beach sands in India is derived from gneisses. These minerals also occur as microscopic constituents in many igneous and meta- morphic rocks. Rutile needles occur in quartz and the rock- forming silicates. River or beach sands containing rutile, ilmenite, or titaniferous iron ore are worked in many places, notably on the India beach and on the northeast coast of Florida. For the properties of the various minerals mentioned, reference to any text on mineralogy can be made. Origin. Black beach sands,of course, owe their presence to the mechanical disintegration of titanium and magnetite-bearing rocks. A gravity sorting by rivers and waves results in concen- tration of ilmenite, etc., along with other heavy, minerals like garnet, zircon, monazite, and others. Sometimes cassiterite and gold are associated. The accepted theory of origin of concentrations of titanium ore in the usual igneous rocks has long been that such 5 deposits were early magmatic segregations. These segregations may either have remained in place or may have been re-fused and injected into the cooled residual rock. In the latter instance, the re-fused iron-titanium ore or rutile-apatite ore would be found as dikes cutting the parent rock, or as stratiform masses in a gneissoid igneous rock. Perhaps the re-fusion is due to a concentration of mineralizers in the mass of first-formed crystals after the rei-- idual magma has been drawn off. The attendant release of pres- sure would have the effect of keeping them solid, but the miner- alizers oppose this tendency to an unknown degree. At any rate, there is a possibility for this origin of the segregations. For the t itaniferous iron ores of New York, Quebec, and Ontario, Osborne has indicated a different origin, based on the following facts: 1. The contacts between ore and the surrounding anor- thosite are everywhere sharp. 2. Central segregations of ore do not exist. 3. There are no marginal segregations. 4. Anorthosite exhibits a reversal of crystallization order in all places, according to Vogt. Pyroxene is intersti- tial in previously-formed labradorite. Osborne claims that the ores were the last minerals to crystallize out, the order of crystallization being: plagio- clase, augite, ore. All gradations in the perfection of this separation have been observed. A pressing-out of the residual Fe-Ti rich liquid, was probably due to earth movements, as the anorthosite shows evidence of it. The temperature of the ore 6 formation was probably 8000 to 10000 d. The presence of concordant, or sill-like, bodies of ilmenite and olivine in gabbro is not definitely explained. The olivine may be a reaction product, but probably is a first- formed crystal product. The reversal of the order of crystallization in a mag- ma is not an unusual exception to Rosenbusch' law that the order is from basic to acid; i.e., iron ores first. Bowen, Teall, and Vogt, have observed it. Rogers and Tolman have concludedthat mineralizers are responsible, especially in the case of sulphides. In pegmatites, the presence of ilmenite shows conclusively that mineralizers were important. Distribution A. Domestic distribution: 1. Alabama. Rutile was reported in Chilton County by the state geological survey in 1874. It is associated with peg- matite dikes in a pre-Cambrian mica schist. 2. Arkansas. Rutile, octahedrite, and brookite (all forms of titanium dioxide) occur at Magnet Cove associated with nepheline syenite. 3. California. A black sand in Santa Cruz County, on the shore of Monterey Bay contains 16% of T10 2 as ilmenite, together with magnetite and martite. The richest deposits form irregular ores- cents 100 to 200 feet long and as much as 50 feet wide, ad may be 5 to 6 inches thick. These beds overlie one another, and are separated by beds of lean sand several feet thick. 7 Los Angeles County has two sources of titanium: in the San Gabriel Mts., south of Soledad Canyon, and along the Pacific beach from Redondo to Palos Verdes. At the former locality, magnetite and ilmenite form segregations in an anorthosite (pure labradorite). The beach sands at Clifton, south of Redondo, contain a lenticular black sand body which extends 24 miles, and varies from 14 inches to 9 feet thick, with an overburden of gray and white sand. The black sand contains zircon. This deposit is supposedly a delta formed by an old outlet of the Los Angeles River. Before closing down at the end of 1928, the Burdick Mineral Corporation concentrated this sand by wet tabling and dry magnetic separation into clean magnetite and ilmenite. Previous shipments of ilmenite averaged over 7,600 tone per year, with a TiO 2 content of from 15 to 52 percent. In San Bernardino County, an ore oarying about 35% rutile was reported, and could be concentrated to 90%. 4. Colorado. Three localities are known.