US930028A - Method of reducing ores. - Google Patents

Description

FREDERICK M. BEGKET, or NIAGAItA FALLS, NEW YORK.

METHOD OE REDUCING QRES.

Specification of Letters Patent.

Application filed May 11, '1909. Serial'No. 495,217.

Patented Aug. 391909.

To all whom it may concern:

Be it known that I, FREDERICK M. BECKER,

' a subject of the King of Great Britain, residaration of the charge.

ing at Niagara Falls, in the county of N iagara and State of New York, have invented certain new and useful Improvements in Methods of Reducing Ores, of which the following is a specification. 1

This vention contemplates the employment as a reducing agent for ores, and more particularly. for the oxid ores of such refractory metals as chromium, tungsten, molyb- .denum and vanadium, of certain borids or alloys or compounds of boron, and particularly the borids of the alkali earth metals, as calcium borid, for-example, and carbon borid. The use of these reducing agents presents particular advantages in the production of metals or afloys which are required to be low I in carbonand silicon, and more particularly in such cases where the presence of a small roportion of boron in the final roduct is either advantageous or unobjectlonable. For example, chromite may be directly reduced by an alloy of calcium and boron which may be either a borid of calcium or an alloy containing either calcium or boron in excess,

the resulting product being a ferro-chromium which is low in carbon or substantially free therefrom. In case the alloy employed contains also such reducing agents as carbon or silicon, or other impurities or constituents capable of exerting a reducing effect upon the constituents of the ore under the furnace conditions, these' impuritiesor constituents are taken into account in the prep- Compounds, and more particularly oxidized compounds, of other refractory metals as tungsten, molybdenum and vanadium may be similarly treated. Similarly, chromite or other ore of a refractory metalmay be reduced by carbon borid, both elements of the reducing agent being oxidized in course of the operation.

Although carbon is present in. considerable I proportion in the reducing agent, it is found that it shows but little tendency to enter into robably because the carbon of the initial 0 arge exists in a combined state and is therefore not readily dissolved or absorbed by the portions of the metal first reduced. p

The reducing agents may. be used 1n sub stantially the proportion required to combine with the oxygen of the charge, or in somewhat smaller or greater proportion, depending upon the character of the product desired and whether boron is a desirable or noninjurious constituent thereof. which it is desired to produce a product low in boron, the ore is preferably employed in In cases in excess on the other hand, where boron is I unobjectionable oris a desirable constituent of the product, a somewhat higher efficiency of operation may be secured by using a slight excess of the reducing agent or such excess as may correspond to the desired boron content of the product. by the presence in the c arge of abase capabe of uniting with the oxid of boron produced, In case calcium borid 'is used as a reducing agent, this base is provided wholly "or in part by the oxidation of the calcium, sup lemented by such bases. as may be normal y present in the ore. Most commercial chronntes contain from 8 to 15 per cent. of alumina and a similar proportion of mag nesia and to the extent of their resence these serve the purposes of a basic ux. In case of ores free from basic constituents, or in case of the deficiency of such constituents, a'suitable basic flux, as lime, is added as reuired, the object being the formation of a s ag having a suitable fusing point and a proper degree of fluidity at the working temperature of the furnace. Obviously, an

The 0 eration is facilitated acid flux may be added should the constitution of the charge'require it for the production of a proper slag.

The reduction is preferably carried out in an electric furnace, and where a fused metallic roduct low in boron is required, the use of t e electric furnace, or of a furnace capable of afiording a like high tem erature, is probably essential. The electro as may be of carbon, or of a refractory metal or alloy suitably water-cooled, in accordance with the proportion of carbon permissible in the roduct. The lining of the furnace shou d be chosen with reference to' the composition of the slag to resist so far as possible its corrosive effect. In case very low ercentages of carbon are not required, the furnace may have a hearth or lining of carbon. The oper ation is preferably substantially continuous in haracter, the char e materials being suppli d as required an the molten roducts ta ped from the furnace. The s age. are ad irantageously utilized for the production of b0rates,; as for example the borates of the alkali metals, or they maybe reduced by carbon in a separate operation. In the latoccurring in certain claims, I mean v, such ter case the boronsconstituent is recovered,

usuall in the form of an allo with the other reduci le constituents .of t e lag, as for example, analloy of boron wit, silicon, or with silicon and calcium, often in conjunction with a considerable proportion of the metal, as chromium, etc., ori inally reduced in'this form the boron may e repeatedly "utilized" for the reduction.

By the expression refractory metals metals as require the application of heat to the charge to maintain the reacting temperature for their reduction by boron or alloys or compounds of boron with production of a reduced metal free or substantially free from the unoxidized reducing agent, the

I claim 1. The method of reducing ores of refractory metals, which consists in smeltin a reaction not being self-propagating in charac I ter.

charge containing such ore and calcium 3. The method of reducing oies of refractory metals, which consists in smelting a charge containing such ore and a borid, thereby producing a metal or alloy and a slag containing boron,- and smelting said slag to recover boron therefrom.

4. The method of reducing ores of refractory metals, which consists in smelting a charge containing such ore, a .borid and a basic flux, thereby producing a metal or alloy and a slag containing boron, and smelting said slag to recover boron therefrom.

5. The method of reducing ores of refractory metals, which consists in electrically smelting a charge containing such ore and a bori 6. The methodof reducing ores of refractory metals, which consists in electrically smeltinga char e containing such ore and a borid of an alka iearth metal.

In testimony whereof, I aflix my signature in presence of two Witnesses;

FREDERICK M. BECKET. Witnesses:

GEORGE O. VFURNESS, J N. DEINHARDT.