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NATURAL RADIOACTIVITY CONTAMINATION PROBLEMS

NORM REPORT NO. 2

August 1981

Published by Conference of Radiation Control Program Directors, Inc. NATURAL RADIOACTIVITY CONTAMINATION PROBLEMS

REPORT NO. 2

A REPORT OF THE COMMITTEE

Prepared pursuant to PHS Contract Number 223-79-6010 which is partially funded through EPA Interagency Agreement D7-0968

Printed August 1981

Prepared by

CONFERENCE OF RADIATION CONTROL PROGRAM DIRECTORS, INC. With the cooperation of

U. S. NUCLEAR REGULATORY COMMISSION

U. S. DEPARTMENT OF HEALTH AND HUMAN SERVICES Bureau of Radiological Health and

U. S. ENVIRONMENTAL PROTECTION AGENCY

Office of Radiation Programs PROCESSING

The titanium industry has two principal products, and titanium metal. The most common titanium are , , leucoxene, and . Other lesser titanium sources are titanium slag, titaniferous iron ore, sphene, , Brookite, and magnetite. Iron percentages in titanium ores can range from a fraction of a percent (rutile) to as much as 55 percent (ilmenite). Weathering of ilmenite causes oxidation and leaching of the iron content with a final product of almost pure titanium dioxide known as leucoxene. Compositions of some of the more common ores are shown in Table 1. Much of the ore originates in beach and fluvaiile sand deposits which also contain monazite. The monazite in turn contains uranium and thorium decay chain radionuclides. The monazite content of the deposits (and therefore uranium and thorium chain content) varies from location to location. The monazite content of the titanium ore fraction depends on how well the monazite has been removed before shipping from the mine. Titanium processing facilities which have operated for many

years would be expected to have older wastes with higher levels of radioactivity than newer facilities.

Titanium metal is currently produced in the U. S. primarily using rutile and leucoxene from Australia. Titanium pigment is produced principally from rutile, anatase, ilmenite, and slag. 2 ' 3

Titanium metal is produced by chlorination of rutile, blends of rutile with leucoxene, or of other concentrates with high titanium dioxide content. The chlorination process is a modified Kroll process (similar to the process used in

-49- zirconium production). The titanium chloride is reduced with magnesium or sodium 10 •

9 titanium sponge which is subsequently converted to ingots." See Figure 1. B| Titanium dioxide pigments are made either by a chlorination process or by an older sulfate process. High TiO2 content ores (rutile, or ilmenite and rutile £ substitutes) in the chloride process are converted to volatile chlorides. Titanium dioxide is then recovered by vapor phase oxidation of TiCl4. ^

In the sulfate process, lower TiO2content ilmenite or slag is converted to water fe mm soluble sulfates. Titanium dioxide is recovered by hydrolysis of high titanium oxide solutions. Titanium dioxide pigments have been produced in the U. S. since 1918 using || the sulfate process. This process was used exclusively until the igSO's when the — chlorination process was introduced. (See Figure 2.) Large quantities of wastes are generated during the production of titanium B| dioxide. In 1972 domestic titanium dioxide plants produced about 1.7 million metric tons of iron-acid sludge and 146 thousand metric tons of iron-chloride sludge. •*• ^ir^^.4.Most ^^H of the radioactivity associated with the incoming ores would be expected to go with ^ these wastes. The radioactivity content of these wastes should also vary depending on source of the ores. Ore in 1972 was produced in the U. S. in Florida, Georgia, New • York, and New Jersey. Radioactivity associated with one processing plant is shown in Table 2. I

In 1974, U. S. consumption of ilmenite, rutile, and titanium slag amounted to m± 588,000 short tons (contained titanium). Of this amount, 92 percent was used for 4 & pigment manufacture. The remainder was used for manufacture of titanium sponge • (metal), welding rod coatings, carbides, and in ceramic and glass formulations.

In 1979, six firms using 10 plants were producing titanium dioxide in the United • States. & In 1980 there were three titanium metal producing plants operating in the United States. Two of these plants purchased TiCl. from a pigment plant while the |j third plant produced metal from rutile and leucoxene ore. -50-

I For comparison purposes, Table 2 can be related to the following levels

1. The normal radioactivity content of natural soil is about

1 pCi/g of U-238, U-234, Th-230,Ra-226, Pb-210 and Po-210 (Uranium Decay Series)

1 pCi/g of Th-232 and Th-228 (Thorium Decay Series)

0.046pCi/gofU-235

2. The radioactivity content of average ground water is about

0.1 to 20 pCi/L of U-238 +U-234

3. Drinking water is regulated at

5 pCi/L of Ra-226 + Ra-228 TABLE 2

TITAHIUM-CHLOHINATION PROCESS AUSTRALIAN ORE

RADIONUCLIDE CONCENTRATION (pCi/g)!

210 226Ra Pb 234. 38,, 230Th 232Th MATERIAL

7.2 ± 2.6 0.6810.24 14.0 ± 1.4 17.0 ±6.0 1.2±0.4 2.0 ± 0.9 15.0 ±2.0 8.5 l 1.2 RUTILE 14.0 ± 1.4 11.0 ± 2.1 0.5910.27 12.011.6 10.0 ±2.9 10.0±3.3 11.0 ±5.2 12.0±1.9 12.0 l 1.1 LEUCOXENE 11.0 ± 1.4

CHLORINATOR < 0.5 0.3410.06 8.3 ±0.6 15.0 ±0.7 11.010.6 11.0 ± 0.6 4.2±0.9 3.3 * 0.6 BOTTOM DUMP 9.0 ± 0.6 30.0 ± 1.1 0.87 ±0.10 26.0 i 1.8 36.0 ±5.3 7.6±1.6 7.5 ± 1.5 17.0*3.5 30.0 1 2.2 SLUDGE POND 27.0 ± 1.8 39.0 ± 2.8 36.0 * 2.1 OLD SLUDGE 58.0 ±3.5 1.6 ±0.14 57.0 ±3.6 77.0 ±9. 2 4.5±0.9 4.6 ± 1.0 25.0±5.3 < 1.6 < 0.8 TITANIUM SPONGE 0.69 i 0. 19 <0.l 0.44 ± 0.13 0.35 + 0.21 <0.3 <0.4 <0.2

LIQUID WASTE STREAMS (pC1/l)

210 210Po 9^4 235u 238u 230Th 232Th 228Th 226R(| Pb MATERIAL "*U _. ———— —————— —

< 6.6 < 3.6 ALPHA DITCH 3.1 * 0.6 < o.2 1.8 10.5 2.0 ±1.0 < 2.0 <2.0 1.2 ± 0.2 1200 1400 ± 100 PARSHALL FLUME 3700 ± 600 <74.0 3300 1600 3300 ±700 1200 ± 300 1600 ±400 3900 i 1200

PROCESS WASTE TO LEACH LIQUOR 30.0 ± 10.0 26.0 ± 4.0 POND 13.0 i 2.0 < o.59 12.0 12.0 14.0 ±5.0 5.4 ± 2.6 7.9 ±3.4 7.5 ± 2.2 Lost 5.2 ± 3.8 CAUSTIC POND 6.9 ± 2.2 < 0.63 5.7 12.0 3.8 ±3.3 < 2.9 < 2.9 4.8 ± 1.4 I TABLE 1 I Titanium Ores

Ore Composition I

Rutile Ti02 I

Umenite FeTtO3

Leucoxene Ti02 Anatase Ti0 I Perovskite Sphene CaTiSiO I I I I I I I I I I I -51- I I IMPORTED ORE (RUTILE) •

0 GASEOUS EMISSIONS ^ LIQUID WASTE FLOTATION REAGENTS O SOLID WASTE A COKE CHLORINE — ? ——— ^ HWATER <•

L FUEL 1ILMENITE) 1 ^ MINING CHLORINATION AND PURIFICATION COAL FLUXES A ( 3 SMELTING

ARGON TITANIUM Mg OR Na HSCRAP HI FUEL , > <: ^———^ [^ [? x~^ / \ X U 5 6 7 TITANIUM __xj TITANIUM . MELTING AND V -J TITANIUM TETRACHLORIDE 7 REDUCTION ———— > V SPONGE ) INGOT CONDITIONING FABRICATION -n METAL

Figure 1. Titanium metal production ALUMINUM CHLORIDE AIR OR OXYGEN

?

PURIFIED CHLORINE FOR REUSE TITANIUM *^ OXIDATION TETRACHLORIDE " FROM PROCESS 4 \f

CHLORIDE PROCESS WATER I——COATING AGENTS FUEL

FINISHING AND DRYING OPERATIONS FUEL

CALCINATION

WATER 1 HYDF ILMENITE ORE ————————————> 0 GASEOUS EMISSIONS <• J*. LIQUID WASTE SOLID WASTE 1?£^k ' 1 ——— > DIGESTION. T ~j CRYSTALLIZATION •^ HYDROLYSIS AND , BIFArHINR

SORAL ^ SLAG •*

ALTERNATE SULFATE PROCESS

Figure 2. Titanium dioxide production' References

1. Industrial Process Profiles for Environmental Use: Chapter 26. Titanium Industry. EPA-600/2-77-023Z. February 1977. Vishno S. Katari and Timothy W. Devitt. Industrial Environmental Research Laboratory. ORD/USEPA Cincinnati, Ohio 45268. 2. Industrial and Rocks (Nonmetallics other than Fuels). Stanley J. Leford, Editor-in-Chief. 1975. American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. New York, N.Y. 3. Titanium - Its Occurrence, Chemistry, and Technology. September 1966. Jelks Barksdale. The Ronald Press Company. New York, N.Y. 4. Minerals Facts and Problems - Bicentennial Edition. Bureau of Mines Bulletin I 667. 1975 Edition. U. S. Bureau of Mines. U. S. Department of Interior. 5. Donald W. Hendricks, Director, ORP Las Vegas Facility, USEPA, Las Vegas, I NV. Private Communication.

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