US1035919A - Reduction of boron compounds. - Google Patents

Description

FRANK J'. TONE, OF NIAGARA FALLS, NEW YbRK.

REDUCTION OF BORON COMPOUNDS.

No Drawing.

Specification of Letters Patent.

Application filed January 18, 1909.

Patented Aug. 20, 1912.

Serial No. 472,903.

To all whom it may concern:

Be it known that I, FRANK J. TONE, a citizen of the United States, residing at Niagara Falls, in the county of Niagara and State of New York, have invented a new and useful Improvement in the Reduction of Boron Compounds, of which the following is a specification.

This invention relates to the reduction of boron compounds and the manufacture of boron alloys, and especially refers to the manufacture of alloys of boron with iron. The reduction of the element boron has heretofore ofiered many difficulties, inasmuch as it requires very high temperatures, but owing to the volatility of boron compounds at high temperatures it is difficult to accomplish a reduction without considerable loss of the ore.

My invention refers to a particular method of carrying out the process of reduction in an electric furnace which obviates these large volatilization losses and enables one to obtain alloys of higher boron content and to operate with greater efficiency than has heretofore been possible.

I prefer to use as an ore of boron, colem anite, which is one of the ores most easily available commercially and which consists principally of calcium 'borate having the formula Ca,B,,O,,(5H O). The colemanite is preferably first calcined to free'it from the combined water and then a charge is formed consisting of colemanite 50 parts, carbon or coke 17 parts and iron oxid in the form of mill scale, 33 parts, these prop0rtions of the ingredients being by weight. These materials are first ground to powder and then thoroughly mixed. The electric furnace employed for reduction is of the well known type with vertical electrodes depending into the furnace pot or chamber. The chamber is formed of refractory material and preferably lined with carbon.

When the furnace is partially filled with charge and the current turned on the calcium borate quickly fuses and unites with the iron oxid forming a fluid conductive bath. This bath acts as a conductor for the current from one electrode to the other and serves as a resistor for the generation of the heat necessary to accomplish reduction.

lVhen the bath is sufficiently heated the carbon reduces the boron from the calcium borate, this reduction being the more easily-accomplished on account of the presence of the iron which is also simultaneously reduced. The boron-iron alloy formed settles to the bottom of the furnace and as the bath is gradually depleted of boron and iron, more charge is added. \Vhen the bath becomes too high in lime a part of it is tapped out along with the alloy. New charge is then added and the process continued in a practically continuous manner.

I have found that by maintaining the bath as a resistance conductor and as the principal heating means, the great volatiliza tion losses which occur in other methods of operation are avoided.

I have particularly described the process as applied to the production of alloys of boron and iron, but by substituting other ores in place of iron, as for example copper, it is possible to obtain corresponding alloys of boron with these metals. It may also in certain cases be desirable to add metalliferous material in reduced or metallic form instead of, or in addition to, the ore.

Having now described my invention, I claim:-

1. The process of reducing boron compounds, consisting in forming a fused bath of a mixture of boron compound, fluxing material, reducing agent and metalliferous material, inter-posing said bath as a resistance-conductor between electrodes, said bath forming the complete circuit between said electrodes, passing through it current sufficient to reduce the boron compound and metalliferous material to form boron alloy, but insufficient to reduce the fiuxing material, and collecting the said alloy.

2. The process of making boron alloys, consisting in forming a fused bath of a mixture of calcium borate, reducing agent and metalliferous material, inter-posing said bath as a resistance-conductor between electrodes, passing through it current sufficient to reduce the boron and metalliferous material to form boron alloy, but. insufficient to reduce the calcium, and collecting said alloy.

The process of making ferro-boron, consisting in forming a fused bath of a \mi-xture of calcium borate, carbon and iron, In testimony whereof I have hereunto set iriterposgng said 1bath das a resistanfie-conmy hand.

ductor etweeli e ectro es 'passing t rough it current sufiicient to redilce the bgron and FRANK 3 5 alloy it with the iron forming ferro-boron, Witnesses:

but insuflicient to reduce the calcium, and F. I. PIERCE,

collecting the ferro-Toeron. W. A. DWYER.