New Zealand. The company reported that it will establish grade and continuity of the ore to its lowest existing levels. Fur

thermore, old tailing dumps that contained a moderate grade of antimony, were being assessed.

At College Park, Md., the U.S. Bureau of Mines developed a method for removing antimony from secondary lead by forming an insoluble aluminum-antimony intermetallic compound.2 Optimum conditions for the formation of the aluminum-antimony compound in a lead alloy containing 2 percent antimony were established. These variables and their optimum conditions for antimony removal are: (1) Inert gas protective covering, (2) 820° C reaction temperature and 350° C filtration temperature, (3) 1.38 molar ratio of aluminum to antimony, (4) stirring for 15 minutes between 50 and 100 revolutions per minute, and

(5) woven glass cloth filter medium. Tests performed under these conditions provided an overall recovery of 90 percent of the lead containing as low as 0.9 percent antimony.

Two recent British patents involving antimony were issued. One patent described a stagewise, fluidized-bed process in which ore is preroasted using a separate supply of a free oxygen-containing gas to volatilize the bulk of the antimony.3 The pre

2 Amey, E. B., D. Montagna, D. A. Wilson and J. M. Marchello. Removal of Antimony from Lead -Two Percent Antimony Alloy. Secondary Raw Materials, v. 9, No. 5, May 1971, pp 71-74.

3 Fabrik, A. G. (assigned to Badische Anilin & Soda). British Pat. 1,232,218, May 19, 1971.

roasted material is then fully roasted in a second stage with a separate supply of a free oxygen-containing gas. In the other patent, a process for fire refining of molten copper sulfide ores to produce high-grade copper while recovering antimony and other metals present in commercial amounts is described.4

The Electrochemical Branch, Naval Research Laboratory, in Washington, D.C., published a paper in which crystallization of PbSO4 on anodes of lead-antimony alloys was evaluated.5 The morphologies of crystals of PbSO4 depositing on 5-percent antimonial lead alloy in 1.25 specific gravity H2SO4 were examined by electron microscopy. The crystals formed on open circuit stand and during discharge of PbO2 coatings, developed by electrochemical cycling, were examined. Well-developed

prisms, dendrites, and hopper crystals were observed. The discharge of the antimonial coatings appeared to be limited by the crystal growth rate.

The result of the investigations of the aluminum-antimony system 6 and the constitutions and solidification microstructures of some pure and impure lead-antimonytin-arsenic alloys 7 were reported.

* Queneau, P. E., and C. E. O'Neill (assigned to International Nickel Co.). British Pat. 1,218,167, Jan. 6, 1971.

5 Burbank, J. Crystallization of PbSO4 on Anodes of Lead-Antimony Alloy. J. Electrochem. Soc., v. 118, No. 4, April 1971, pp. 525-530.

Lyttel, J. E., P. V. Dembawski, and L. S. Castleman. Irregular Growth of AISb in Solid Aluminum-Solid Antimony Diffusion Couples. Met. Trans., v. 2, No. 1, January 1971, pp. 303-304.

Kerr, H. W. The Constitutions and Solidification Microstructures of Some Pure and Impure of Lead-Antimony-Tin-Arsenic Alloys. J. Inst. Metals, v. 99, August 1971, pp. 238-242.

Environmental Impact.-The inclusion of asbestos on the list of hazardous air pollutants is beginning to effect the industry. One application, sprayed insulation, has been outlawed in several cities and States, and would be banned under proposed Environmental Protection Agency (EPA) regulations. There have been no serious losses of markets yet, except for talc that contains tremolite, but new markets are extremely slow in opening up.

The manufacturer not now having asbestos among his necessary raw materials is reluctant to purchase it because of very strict inspection and regulation of the working areas by the Labor Department Office of Safety and Health Administration (OSHA), and of plant effluents by EPA.

In 1971 asbestos workers in mines and mills were protected under the Metal and Nonmetal Health and Safety Act administered by the Bureau of Mines. The Bureau's inspectors were changing over from measuring all particulate matter using a particle impingement method and reporting in million particles per cubic foot, to using a membrane filter and microscopy method, and reporting in fibers longer than 5 mi

crons per milliliter. The acceptable Threshold Limit Value (TLV) was five fibers per milliliter greater than 5 microns.

EPA was proposing regulations that would give it jurisdiction over any possible emission source to the ambient air. This would include all activity at the mine site and mill that occurs in the open, such as drilling, blasting, loading, hauling, etc. EPA stated that there is no suitable technique available for measuring asbestos emissions in ambient air; in lieu of specific standards, EPA proposed establishment of restrictions on operating techniques.

OSHA is using the membrane filter technique to check on the working conditions of the people using asbestos in product manufacture and applications. In 1971 its TLV was five fibers per milliliter greater than 5 microns. The National Institute for Occupational Safety and Health proposed a level of two fibers per milliliter greater than 5 microns.

The Clean Air Act gives the States jurisdiction over emissions of hazardous air pollutants, provided their regulations equal or exceed those proposed by EPA.

U.S. mines produced 4 percent more asbestos in 1971 than in 1970. The value increased 14 percent. Four States produced asbestos; California, with 67 percent, was the leader, followed in order by Vermont, Arizona, and North Carolina.

Although 1971 saw the entire West Coast in the economic doldrums, the California segment of the asbestos industry continued to grow. The 10 percent increase in production to 87,144 tons was led by Pacific Asbestos Corp.'s mine in Calaveras County. The largest producing County was Fresno, with Coalinga Asbestos Co. and Atlas Asbestos Corp. mines. Union Carbide Corp. had very significant production in San

Benito County. The State's increased production realized a $1,444,190 increase in value.

GAF Corp.'s mine in Orleans County, Vt., showed an apparent production decrease of 5 percent without an attendant loss in value. With only Jaquays Mining Corp.'s mine in Gila County operating in 1971, Arizona production decreased 11 perWith a new production site in Transylvania County to go with their other two in Yancey and Jackson Counties, the production in North Carolina of Powhatan Mining Co. increased 11 percent. U.S. asbestos producers and mine sites are as follows:

cent.