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Publication numberUS3893915 A
Publication typeGrant
Publication dateJul 8, 1975
Filing dateJun 14, 1973
Priority dateJun 14, 1973
Publication numberUS 3893915 A, US 3893915A, US-A-3893915, US3893915 A, US3893915A
InventorsMercade Venancio V
Original AssigneeEngelhard Min & Chem
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Fluorspar ore flotation
US 3893915 A
Flotation of fluorite from calcareous gangue with a fatty acid collector in an aqueous alkaline ore pulp is improved by adding an alkali metal bisulfite salt or an alkali metal thiosulfate salt before adding the collector.
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Description  (OCR text may contain errors)

United States Patent [191 Mercade 1 July 8,1975

[ FLUORSPAR ORE FLOTATION [75] Inventor: Venancio V. Mercade, Metuchen,

[22] Filed: June 14, 1973 [21] Appl. No.: 369,892

[52] U.S. Cl. 209/166 [51] Int. Cl 303d 1/02 [58] Field of Search 209/166, 167

[56] I References Cited UNITED STATES PATENTS 1,254,173 l/l9l8 Terry 209/167 1,274,505 8/1918 Readford 209/167 2 ,263,552 11/1941 Anderson 209/166 2,401,651 9/1946 Clemmer 209/166 2,497,863 2/1950 Clemmer 209/166 3,430,765 3/1969 Allen 209/166 X OTHER PUBLICATIONS Chem. Abst. 65, 1966, 8397b.

Chem. Abst,, 69, 1968, 78829w.

Mack, Chern. Dictionary, Third Edition, 1944 pgs. 425 & 429.

Primary Examiner-Robert Halper Attorney, Agent, or Firm-Melvin C. Flint; Inez L. Moselle [57] ABSTRACT Flotation of fluorite from calcareous gangue with a fatty acid collector in an aqueous alkaline ore pulp is improved by adding an alkali metal bisulfite salt or an alkali metal thiosulfate salt before adding the collector.

5 Claims, No Drawings dichromate salts 1 FLUORSPAR ORE FLOTATION' BACKGROUND oF THE iNvENTioN Fluorite (CaF- frequently occurs in fluorspar ores containing appreciable quantities of calcareous gangue. especially calcite. Fluorite can be floated from the calcite and silica-and silicate gangueminerals with a fatty acid collector. Preferably silicate dispersant is employed. However, fluorite and calcite' have similar surface properties .and the grades and/.or recoveries of the fluorite concentrateszgenerally leavesomething to be desired when the ores are rich in calcite.

Various reagents have been suggested for use to improve the selective flotation of fluorite from calcite. Among these reagents are metalisalts, which may be added to sodium silicate'to form gels, oxidants such as and gangue depressants such as quebracho. I

An object of the invention is to improve the efficiency with which fluorite can be floatedfrom calcere-- ous gangue with a fatty acid collector in an aqueous alkaline ore pulp. 2

The essence of the present invention resides in adding a small amount of an alkali metal bisulfite salt, an

alkali metal thiosulfate salt or mixtures thereof, to an aqueous alkaline pulp of fluorspar ore before adding a fatty acid collector and subjecting the ore pulp to froth flotation to produce a fluorite-rich froth product and a tailings which is a concentrate of calcareous and sili- CCOUS gangue.

The alkali metal bisulfite and thiosulfate salts used in the practice of my invention are capable of reacting with calcium ions to form highly soluble calcium salts. It is believed that the outstanding effectiveness of such salts in improving the selective flotation of fluorite from calcite is attributable to the selective solubilization of calcium from the fluorite mineral particles. This in turn results in improved collection by the fatty acid reagent. Initially, the beneficial effect of these salts on the selective flotation of fluorite from calcite wasattributable to the fact that the salts were functioning as reducing agents. However, it was found that a wide variety of other reducing agents, including a hydrosulfite salt, were not beneficial. Consequently, the initial theory was discarded.

DESCRIPTION OF THE INVENTION In putting the invention into practice, the fluorspar ore is ground to a size sufficiently small to liberate the fluorite, e.g., 100 mesh (Tyler) or finer. The pulp is then alkalized by adding soda ash or caustic soda. Preferably, the pulp is dispersed with a mineral dispersant such as sodium silicate or a sodium silicate-polyvalent metal salt hydrosol of the type used in the flotation process described in U.S. Pat. No. 3,337,048. An alkali metal bisulfite or thiosulfate salt is generally used in amount in the range of about A to 2 lbs/ton. The salt is added before adding the fatty collector which may be, for example, oleic acid or tall oil. Preferably, starva- A sample of the minus mesh ore was wet' ground 'to minus 325 mesh Tyler) -in a rod mill. The ore was tion amounts of collector reagent are used. Flotation is 1 The following examples are given for illustrative pur- I poses.

pulped in water at about 25 percent solids.-The pulp 'was alkalized by adding soda ash, 10lbs./ton andthen it was dispersed by incorporating a hydrosol obtained by' mixin'g a 1- percent solution of ZnSO.;.'7l-I O with a "solution of 0 sodium silicate diluted to 5 percent and containir'igthe equivalent of 15'lbs./t on O and 1.9 lbs/ton ZnSO .7I-I O.' 4

Afsulfide flotation was carried out after adjusting pH to 9.5 with soda ash and adding Z-6 (potassium "ainyl xanthate) in amount of 0.25,lb ./ton. Dowfroth 250 was used as the frother in amount of 0.20 lb./ton. After conditioning the pulp for 5 minutes, a sulfide froth was removed for 5 m inutes'.' 'j

In one test carried out in accordance with this invention, port'ions of tlie tailings from the sulfide flotation were treated with sodium bisulfite (0.5 lb./ton) added as a 1 percent aqueous solution, followed by conditioning for 5 minutes, addition of oleic acid (0.36 lb./ton), followed by conditioning for 12 minutes. The conditioned pulp was subjected to froth flotation using a Denver Sub-A cell operating at 900 rpm. The rougher froth concentrate was cleaned 3 times by flotation. The procedure was repeated using 1 lb./ton sodium bisulfite. The froth products using 0.5 and 1.0 lb./ton bisulfite as activators were assayed and recoveries were obtained by weighing products. 7

A control test was carried out with another portion of the tailings from the preliminary sulfide flotation.

Results are summarized in table form.

The term flotation index which is used in the table is a calculated value that is indicative of flotation efficiency.

The following equation is used to compute flotation index.

Fl 4 d grade X Recovery (actual) otauon m ex grade X Recovery (perfect separation) The grade of a perfect separation would be 100 percent and recovery would be 100 percent.


based on head assay of 23.2 percent CaCF,

Data in the table show that the flotation index was improved by adding 0.5 and 1 lb./ton sodium bisulfite to the pulp before conditioning the pulp with oleic acid and floating fluorite. The higher index was attributed to both higher grade and higher recovery when using 1 lb./ton NaHSO When using 05 lb./ton NaHSO; the higher index value was due to the higher recovery.

EXAMPLE ll The experimental and control tests of Example [were repeated with the exception that fluorite was floated at pH 8.5. In other tests, fluorite was floated at pH 10.5. In tests carried out in accordance with the invention,

- sodium bisulfite was added in amount of 0.5 lb./ton and it was incorporated into the pulp before adding oleic acid (0.36 lb./ton). It was found that the sodium bisulfite improved grade and increased flotation index at pH values of 8.5 and 10.5. However, recoveries and flotation indices were better when using sodium bisulfite at pH 9.5 (Example I) than they were when flotation was carried out with the same amount of sodium bisulfite at pH 8.5 or 10.5.

EXAMPLE Ill The procedure of Example I was repeated with another source of the ore pulp using 1 lb./ton sodium thiosulfate. The thiosulfate salt was added as a 1 percent solution. The results were similar to those obtained with l lb./ton sodium bisulflte.

I claim:

1; In the froth flotation of fluorite from a calcareous gangue with a fatty acid collector for the fluorite in an aqueous alkaline ore pulp, the improvement which consists in activating said pulp for the selective flotation of fluorite by adding a material selected from the group consisting of alkali metal bisulfite, alkali metal thiosulfate and mixtures thereof.

2. The process of claim 1 wherein said alkali metal thiosulfate is sodium thiosulfate used inamount within the range of A to 2 lbs/ton.

3. The process of claim 2 wherein the fluorite is floated at a pH of about 9.5.

4. The process of claim 2 wherein said alkaline ore pulp is dispersed with sodium silicate.

5. ln the froth flotation of fluorite from a calcareous gangue with a fatty acid collector for the fluorite in an aqueous alkaline ore pulp, the improvement which comprises activating said pulp for the selective flotation of fluorite by adding sodium bisulflte in amount within the range of A to 2 lbs/ton.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. DATED July 8, 1975 INVENTOR(S) i Venancio V. Mercade it is certified that error appears in the ab0veidentified patent and that said Letters Patent are hereby corrected as shown below:

Column 2 line 46 the equation should read:

grade X recovery (actual) Flotation index 100 X grade X recovery (perfect separation) Signed and Sealed this sixteenth Day Of September 1975 [SEAL] Arrest:

RUTH C. MASON C. MARSHALL DANN Allcsling Officer Commissioner nj'PaIenrs and Trademarks

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1254173 *Mar 24, 1917Jan 22, 1918Joseph T Terry JrProcess for the concentration of ore.
US1274505 *Oct 22, 1914Aug 6, 1918Leslie BradfordSeparation of mixed metallic sulfids.
US2263552 *Feb 21, 1940Nov 25, 1941Mahoning Mining CompanyMethod of concentrating fluorspar ores
US2401651 *Dec 28, 1942Jun 4, 1946Mathis John AApparatus for evaporating liquid oxygen
US2497863 *Mar 21, 1946Feb 21, 1950Bruce Clemmer JuliusMethod of concentrating fluorspar ores
US3430765 *Aug 11, 1965Mar 4, 1969Allied ChemBeneficiation of fluorspar ores
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US5061461 *Aug 22, 1990Oct 29, 1991Engelhard CorporationCationic processing of kaolin ores
US5112782 *May 23, 1991May 12, 1992Engelhard CorporationCationically processed calcined kaolin clay
US5717140 *Sep 20, 1996Feb 10, 1998Alliedsignal, Inc.Angular rate sensor electronic balance
US5866816 *Nov 13, 1997Feb 2, 1999Alliedsignal Inc.Angular rate sensor misalignment correction
US6041941 *Jun 24, 1998Mar 28, 2000Boc Gases Australia LimitedReagent consumption in mineral separation circuits
US8931642Jan 13, 2014Jan 13, 2015William D. SimmonsActivated flotation circuit for processing combined oxide and sulfide ores
US9346062Dec 3, 2010May 24, 2016Barrick Gold CorporationSeparation of copper minerals from pyrite using air-metabisulfite treatment
US20110155651 *Dec 3, 2010Jun 30, 2011Barrick Gold CorporationSeparation of copper minerals from pyrite using air-metabisulfite treatment
CN102764700A *Aug 1, 2012Nov 7, 2012中钢集团马鞍山矿山研究院有限公司Preparation method of low temperature resisting fluorite flotation collector
WO2014110518A1 *Jan 13, 2014Jul 17, 2014Simmons William DFlotation circuit for oxide and sulfide ores
U.S. Classification209/166
International ClassificationB03D1/002
Cooperative ClassificationB03D1/002
European ClassificationB03D1/002
Legal Events
Jun 10, 1983ASAssignment
Effective date: 19830328
Apr 16, 1982ASAssignment
Effective date: 19810518