US1360581A - Production of molybdenum compounds - Google Patents

Description

UNITED STATES PATENT .OFFICE.

GEORG RICHTER, OF TEUTSCHENTHAL, NEAR HALLE-ON-THE-SAALE, GERMANY ASSIGNOR, BY MESNE ASSIGNMENTS, TO THE CHEMICAL FOUNDATION, INC.,

CORPORATION OF DELAWARE.

PRODUCTION OF MOLYBDENUM COMPOUNDS.

Specification of Letters Patent.

Patented Nov. 30, 1920.

No Drawing. Application filed July 12, 1917, Serial No. 180,196. Renewed April 19, 1920. Serial N0.

To all whom it may concern Be it known that I, Dr. GEORG RICHTER, a subject of the Empire of Germany, residing at Teutschenthal, 'near Halle-on-the- Saale, Germany, have invented new and useful Improvements Relating to the Production of Molybdenum Compounds, of which the following is a specification.

This invention relates to the process of treating ores or other material containing molybdenum, for instance wulfenite or slags containing molybdenum. For this purpose, the said materials for instance wulfenite after being sufliciently reduced to small pieces or to powder are treated with a watery solution of alkali sulfid, alkali pol sulfid or alkali hydrosulfid, whereby molybdenum is dissolved in the form of alkali sulfomolybdate, whereas lead is transformed to insoluble lead sulfid which remains in the residue. The extraction may be effected at ordinary or elevated temperature, and at ordinary or elevated pressure.

It is well known to produce alkalisulfomolybda-te solution and to precipitate from these molybdenum sulfid by adding an acid, but this method of operating is not desirable, as it requires very troublesome operations when carried out on a considerable scale. Applicant has found a suitable wa for separating the sulfur from the alkalisulfomolybdate and thus obtaining alkali molybdate lyes sufficiently pure of producing molybdenum or molybdate compounds.

from them.

When the obtained sulfomolybdate lyes are treated with new quantities of wulfenite, oxygen is exchanged by sulfur and relatively pure solutions of alkalimolybdate are obtained, whereas lead sulfid is left in the Preferably bothreactionsthe extracting and the sulfur separating processmay be combined by effecting the extfaction accord a s alkalisulfomolybdate lyes by other methods, for instance by treating them with other oxygenated lead compounds or with oxygenated iron, manganese or zinc compounds, preferably with precipitated ferric hydroxid or protoxicl of manganese.

In a modified form the process may be carried out in the following manner :The ore or other material to be treated is reacted upon with a reduced quantity of alkali sulfid (or its equivalent) which is not suflicient to completely transform the molybdenum to alkalisulfomolybdate. In this case, the sulfomolybdate formed in the first place is then at once transformed to alkalimolybdate, by the excess of unchanged wulfenite according to the above given equation.

The same end effect may be obtained by effecting the sulfurizingoperation by a smelting process; For this purpose, the ore or other material is melted with alkali sulfid in the well known manner, but only with a quantity of sulfid not sufiicient to completely transform the molybdenum to alkalisulfomolybdate. On dissolving the molten mass, the reaction between the formed sulfomolybdate and the unchanged wulfenite takes place in the manner heretofore describe I In both cases it is not necessary to employ exactly the theoretical amount of alkali sulfid; an excess of sulfur can always be removed by fresh lead-ore or another desulfurizing agent. In the utmost case, this method of separating the excess of sulfur may also be applied to solutions of alkalisulfomolybdate which are produced by the known process of melting wulfenite with an excess of alkali sulfid and thereafter dissolving the molten mass.

When slags are to be treated -I prefer to employ the melting process instead of the extracting process.

All reactions heretofore described may be efi'ected with ammonium sulfid orwith mixtures generating ammonium sulfid instead of "alkali sulfid.

h s, isstirred during some hours with the waste-water from' the first operation andsponds to 25 kilograms of active sodium sulfid Na swi From the stirred mixture the solution practically containing all the inolybdenum of the wulfenite in form of sodium sulfomolybdate is separated from the formed lead sulfid by decanting and washing, and this solution is when cold stirred in another stirring apparatus with further 100 kilograms of finely ground wul fenite during one hour. From the stirred mixture a pure solution of sodium molybdate is obtained by filtering. The residue of .wulfenite notyet completely changed tolead sulfid, which is left in the stirring appara such an amount of sodium sulfid as-corre- 'fenite are melted with such .a quantitlyg sponds .to. 20 kilograms of activevsodium stirred during several hours with a hot or cold watery solution of the sulfid.

The watery. solution of the molten mass or the stirred mixture contains the molybdenum of the wulfenite in the form of sodium molybdate and may be separated from the lead sulfid formed along with it by filtering and washing.

It may be noted that where I have used the term alkali sulfid in the claims, this term is to include all kinds of compounds formed-between sulfur and an alkali metal t or the ammonium group lfipresented for-in- .stance by'the formulw H 3 I M S M 8 wherein M signifies sodium. lla T generatingalkali reaction and with water and solution thus obtained with wulfenite.

In testimon whereof I aflix my signature s, MHS, MS

or potassium K or ammonium NH and where I have used the term fl ai the specification and claims, I mean the native lead molybdate."

Ieclaim 4 v 1.' The herein: of ':producing-molybdenum compounds from Jrnaterial containing Witnesses: rialcontainmg molybdenum consisting m extracting the said material with a watery solution of alkali sulfid and treating the solution with a desulfurizing agent.

'2. The herein described process of producing molybdenumcompounds from material containing molybdenum, consisting in passing a stream of alkali sulfid lye and an excess of -wulfenite in opposite directions,.so that in the first instance a sulfomolybdate is formed which is then desulfurized by the excess of the wulfenite.

3. The herein described'process of producing molybdenum compounds from material containing molybdenum, consisting in treating the said material with a sulfuriz ing agent and water and treating the solution thus obtained with a desulfurizing agent. v

4. The herein described process ofproducing molybdenum compounds from material containing molybdenum, consisting in treating the said material with a sulfurizing agent and water and treating the solution thus obtained with wulfenite.

'5. The herein described process of producing molybdenum compounds from material containing molybdenum, consisting in extracting an excess of the said ore with a watery solution of an alkali sulfid, the excess of the wulfenite acting as a desulfurizng agent on the alkali sulfomolybdate formedby the action of the alkali sulfid. 6. The herein described process of produc-' ing molybdenum compounds from material containing molybdenum, consisting in'treating thesaid material with a mixture generating alkali sulfids when brought to reaction, and withwate'r and treating the solution thus obtained with a desulfurizing agent.

r 7. The herein described process of producing molybdenum compounds from matemolybdenum, consisting in treating the said material with a mixture sulfids. when brought to treating the in presence 0 two witnesses.

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