Chemistry of inorganic compounds – Treating mixture to obtain metal containing compound – Group vib metal
Patent
1988-02-24
1990-03-20
Straub, Gary P.
Chemistry of inorganic compounds
Treating mixture to obtain metal containing compound
Group vib metal
423 56, 423 57, 75101R, 75108, 75121, C01G 4100, C22B 3436
Patent
active
049100009
DESCRIPTION:
BRIEF SUMMARY
This invention relates to the treatment of tungsten containing ores to achieve extraction of tungsten containing values.
The present invention provides a method of extracting tungsten values from tungsten containing ores comprising:
Step 1: forming a mixture of a tungsten containing ore and a first mineral acid effective to consume the acid consuming substances (such as carbonates) in the ore, and
Step 2: thereafter adding an organic acid or a salt of an organic acid to produce a solution containing dissolved tungsten values.
The method preferably includes the further step of hydrolysing said solution to produce a precipitate containing tungsten values.
A preferred mineral acid for the consumption of acid consuming substances is sulphurous acid which may be added as sulphur dioxide. An alternative mineral acid for the consumption of acid consuming substances is sulphuric acid.
Hydrochloric acid or nitric acid or a blend of any of the above acids may also be used as said mineral acid. The use of sulphurous acid and hydrochloric acid together has advantages but is costly. The use of sulphurous acid to consume acid consumers and the use of sulphuric acid and sodium chloride to providce acidity and chloride ions is particularly preferred.
The organic anions are preferably selected from oxalate, formate, malonate, succinate and acetate. Of these, oxalate ions are preferred as, in general, the use of oxalate ions results in solution of tungsten values at lower temperatures than hydrolysis.
The solution is preferably separated from any undissolved residue prior to hydrolysis.
Chloride ions are preferably added in step (ii) if not already present.
After separation of the precipitate the remaining acid containing solution may be recycled.
The organic anions and chloride ions may be added as the acid or as salts.
Mixtures of organic acids may be used to promote solution of tungsten values.
The tungsten containing ore is preferably in finely divided state as this promotes solution of tunsten values.
Said solution may have direct industrial application but it is preferred that tungsten values be separated therefrom.
In one instance organic anions are added to said mixture at a temperature of 80.degree. or less with 50.degree. C. or less being more preferred.
In another instance organic anions are added to said mixture at boiling temperature.
The step of hydrolysing is conveniently conducted by heating said liquor above 80.degree. C. and preferably boiling said liquor to obtain a hydrolysed tungsten precipitate.
The step of forming said mixture is conveniently conducted by forming a tungsten ore reaction medium containing a mineral acid and thereafter adding organic anions to said medium.
Said medium may contain up to 20% by weight of free mineral acid but preferably less than 10% by weight and less than 3% by weight is most preferred.
Chloride ions are preferably present in an amount of not less than 1% by weight, preferably less than 20% by weight and more preferably less than 10% by weight of said mixture and said organic anions.
The organic anions are preferably added to said mixture in a ratio or at least 1 part by weight to 1 part by weight of tungsten in said ore calculated as WO.sub.3. The use of more than 4.5 parts by weight of organic anion to 1 part by weight of tungsten in said ore calculated as WO.sub.3 is possible but is not preferred as for higher organic anion concentrations high free mineral acid concentrations are required to effect hydrolysis but if such higher free mineral acid ion concentrations can be tolerated then higher organic acid concentrations may be used.
The present invention has application to all tungsten containing ores but is particularly applicable to scheelite and wolframite.
In the case of scheelite the method preferably used includes digestion of scheelite ore with organic anion and mineral acid at a temperature of 80.degree. C. or less, more preferably 50.degree. C. or less, separating non-solubilized material to obtain a liquor containing tungsten values and thereafter heating t
REFERENCES:
patent: 787758 (1905-04-01), Herrenschmidt
patent: 1081571 (1913-12-01), Becket
patent: 1348356 (1920-08-01), Giles
patent: 3047361 (1962-07-01), Hubbard
patent: 3079226 (1963-02-01), Newkirk
patent: 3256058 (1966-06-01), Burwell
patent: 3271104 (1966-09-01), Surls
patent: 3969478 (1976-07-01), Zelikman et al.
patent: 4083920 (1978-04-01), Beaton et al.
patent: 4115513 (1978-09-01), Kulkami et al.
patent: 4167555 (1979-09-01), Ganes
patent: 4168296 (1979-09-01), Lundquist
patent: 4298581 (1981-11-01), Douglas et al.
patent: 4298582 (1981-11-01), Menashi et al.
patent: 4328190 (1982-05-01), Beckstead et al.
patent: 4420331 (1983-12-01), Van't Sant et al.
patent: 4457776 (1984-07-01), Van't Sant et al.
patent: 4533527 (1985-08-01), Farrell et al.
patent: 4624703 (1986-11-01), Vanderpool et al.
patent: 4626280 (1986-12-01), Vanderpool et al.
patent: 4626425 (1986-12-01), Scheithauer et al.
patent: 4741886 (1988-05-01), Vanderpool et al.
Harvey Paige C.
Straub Gary P.
The University of Melbourne
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