production of battery grade manganese dioxide from manganese ore

Aravamuthan, V.

Venkatasubramanian, T.R.

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GOVERNMENT OF INDIA: THE PATENT OFFICE, 214, LOWER CIRCULAR ROAD, CALCUTTA-n.Specification No. 60333, Application No. 60333 dated 27th April 1957. Completespecification left on 27th February 1958. (Application accepted 24th October 1958.)PROVISIONAL SPECIFICATIONIMPROVEMENTS'N OR RELATING TO THE PRODUCTION OF BATTERY GRADE MANGANESEDIOXIDE FROM LOW GRADE MANGANESE ORES.COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESE ARCH, OLD MILL ROAD, NEW DELHI-I, INDIA, AN INDIANREGISTEREDBODYINCORPORATEDUNDERTHE REGIS I'RATIONOF SOCIETIES ACT (ACT XXI Ol!' 1860).The following specification describes the nat Ibre of this in'vention.THIS IS AN INVENTIONBY VEERARAGAV A ARA VAMITH AN AND THIRUMANGALAM RENGASWAMI VENKA-TASUBRAMANIXN, BOTH OF THE CENTRALELECTRO-CHEMICALRESEARCHINSTITUTE, KARAIKUDI. INDIA, BOTHhWIAN CITIZENS.The invented process for the electrodeposition of man-ganese dioxide consists III the addition of 7-12 cc. of nitricacid of 1·42 specific gravity per litre of manganese sulphatesolution in water. The advantages of addition of properamounts of nitric acid as stated above and conductingelectrolysis under conditions herein after claimed in thispatent have not so far been reported in literature.The beneficial effects of addition of nitric aC'id in generll.land more so in quantities stated above to produce batterygrade manganese doxide by electrolysis of manganese s~l-phate solution in water have not so far been reported !t1literature. By such an addition it is possible.(i) to work with high current densities which ar~ .ofthe order of 3 times the anode current denSItIesemployed (30 amps per sq. ft. instead of 9 ampsper sq. ft.) When pure manganese sulphatesolutions are electrolysed commercially to getthe desired quality of manganese dioxide (gam-ma form of manganese dioxide containing notless than 68 per cent. manganese dioxide andnot more than 2·5 per cent. iron, 0·5 per cent.lead, 0·03 per cent. copper, 0·1 per cent. arsenic,etc.,) as in WECCO process described in Chemi-cal Engineering, January 1954 issue;(ii) to keep the cell voltage between 1·8 to 2·2 volts,although in the latest commercial practice(WECCO process) the cell voltage ranges from2·2 to 2'6;(iii) to get an easily stripable deposit with uniformcharacteristics; and(iv) to conduct the electrolysis at about 90°C., i.e., atthe same temperature conditions employed inWECCO process.Forty pounds of manganese dioxide of uniformlyacceptable grade have been prepared by electro lysing man-ganese sulphate solution (obtained from low-grade manga-nese ores by reaction with pickle liquor as covered in theIndian Patent 59713 by the &'""'l1eauthors) after addingnitric acid under the following conditions:Concentration of manganese sulphate: 250 grams ofmanganese sulphate per litre of the 'Solution.4 C.c. of sulphuric. acid of 1·84 specifio gravity perlitre.•10 C.c. of nitric acid of 1·42 specific gravity per litre.Volume of liquid electrolysed: 8 litres.Size of the vessel (inner dimension) 12" X 6,11x 10".Material of construction. . Glass, hard rubber, chemicalstoneware, lead lined, rubberlined etc., vessels.Size of graphite anodes and Graphite plates of about 1/4"cathodes. . thick, 4 inches broad and 12Khigh anc about 10" of the totalheight dipping in solution (3anodes and 4 cathodes) or rodsof 5(8" to 1" inner diameter, 12"height and about 10" of the totalheight dipping in solution (3 rodsarranged in a row forming oneanode or cathode unit-3 suchanodes and four such cathodesare employed).Spacing of the electrodes. 1 inch.Anode current density •- 30 amps. per sq. ft.Voltage across the cell • 1.8 to 2.2 volts.Time of electrolysis • 8 hourd continuous (minimumCui'rent efficiency . period 65% (minimum)CHARACTERISTICS OF THE PRODUCT.Mangane3e dioxideTotal manganeseIron •Carbon. . . •Gangue and acid insoluble82.04%56.15%0'1405%4.82%4.848% (4.82% is oarbon whichis not considered as impurity bu'has beneficial effeots).3.83%3.914 gms/col.ll-. 06IJ pHMoistureReal Density .pH-EMF RelationshipFh• 0Avera.ge energy consumed 0.975 kwh per pound of manga_nese dioxide produced, wherea.ain WECCO process 1 kwh ilneeded to produce 1 lb. of manga.-nees dioxide.:R. BHASKAR P A.I,Patents Officer,Council of Scientific &: Industrial Research..Dated this 23rd day of April 1957.COMPLETE SPECIFICATION.IMPROVEMENTS IN OR RELATING TO THE ·PRODUCTION OF BATTERY GRADE MANGANESEDIOXIDE FROM MANGANESE ORES.COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESE ARCH, OLD Mm, ROAD, NEW DELHI-I, INJiIA, AN INDIANREGISTEREDBODYINCORPORATEDUNDER.THE REGISfRATION OF SOCIETIES ACT (ACT XXI OF 1860).The following specification particularly describes and ascertains the nature of this invention andthe manner in which it is to be performed. ~THIS IS AN INVENTIONBY VEERARAGA VA ARA VAMITH AN AJ.'iD THIRUMANGALAM RENGASWAMI VENKA-TA8UBRAMANIAN, BOTH OF THE CENTRALELECh.o- CHEMICALRESEARCH INSTITUTE, KARAIKUDI, INDIA, BOTHINDIAN CITIZENS.The invented process for the electrodeposition of man-ganese dioxide particularly for the production of batterygrade manganese dioxide from manganese ores consists inadded per every litre of manganese sulphate solutions con-taining 150-250 grams of manganese sulphate per litre a,nd4, to 8 ccs. of sulphuric acid of 1·84 soeci:fic ll'ravitv_ ThAmanganese sulphate solution in water have not so far beenl'eported in literature. By such an addition, it is possible.(i) to work with high current densities which are ofthe order of a hmes the anode current densitizsemployed (30 amps. per sq. ft. instead of 9 ampsper sq. ft.) when pure manganese sulphilte solu-tions are electrolysed commercially to get thedesired quaJit., of manganese dioxide (gammaform of manganese dioxide containing not lessthan 68 per cent.· manganese dioxide and notmore than 2'5 per cent. iron, 0,5 per cent.lead, 0·03 per cent. copper, 0·1 per cent.arsenic, etc.), as in 'VECCO process descrihedin Chemical Engineering, .1'anuary 19:-j.j. issue;(ii) to keep the cell voltage between 1·8 to 2·2 volts,although in tIle latest commercial practice(WECCO process) the cell voltage ranges from2·2 to 2·6;(iii) to get an easily sb'ipPable deposit with uniformcharacteristics; and(iv) to conduct the electrolysis at about 90·C., i.e., ailthe same temperature conditions employed inWECCO process.Forty pounds of manganeose dioxide of uniformlyacceptable grade have been prepared by electrolysingmanganese sulphate solutions <obtained from manganeseores by reaotion with pickle liquor as de.5crib(',1 in ourprior Indian Patent No. 59713) after adding nitric acidunder the following conditions:Concentration of manganese 250 grams of manganese sulphatesulphate per litre of the <olution.4 Cc. of sulphurc acid of 1·84 sp. gr. per litre.10 Cc. of nitric acid of 1·42 sp. gr. per litre.Volume of liquid electrolysed: 8 litres.Size of the vessel (inner dimensions): 12/1 X 6" X 10'/.:Material of comtruction : Glass, hard rubber, chemicalstoneware, lead lined, rubberlined etc., ve'sel<.and GrE'phiteplate" of about i" thick.4 inohes broa~ and J 2" high andabout 10" of the total heightdipping in ,olution (3 anod"s and4 cathodes) or rods of [,/8" to 1"inner dia.meter, 12" height andabout. 10" of the total heightdipping in solution (3 rods arran-ged in a row forming one anodeor cathode unit-3 such cathodesand foU!'such cathodes are empl-ed).I inch.30 amps per Pq.ft.1.8 to 2.2 volt".8 hours continuous (minimumperiod.)65% (minimum)Size of graphite anodescathodes:Spacing of the electrodes:Anode current den ,ity :Volta,ge across the cell :Time of electrolysis:Cilfrent effioieney:,.,PREPARATION OF Mill',;aAlVESE SULPHATEsO LU·TWINS.The starting material for the production of manganesesulphate shall be of any type of manganese ore. Even lowgrade manganese ore containing high iron, silica and alu-. mina contents and in \-..hich the percentage of manganese,varies from 5 to 30 can be used as a starting material.Manganese sulphate suit-';d for electrolysis is obtainedfrom the manganese ores by any standard procedure such11S by roast-reduction followed by leaching \:,ith cell efflu-ent containing dilute ar·id· and small amounts of manga-nese sulphate, etc., and purification OR by treatment withwaste pickle liquor of the Iran and Steel industries suchas the mixtul'e of ferrous s~lphate and dilute sulphuricacid OR by employing other reducing agents such as car-bon, saw dust, sulphur dioxide, iron or the like, in sul-ph uric acid medium, etC.ANALYSIS AND pm"SZCO-OHEMlOAL PROPERTIES.Manganese dioxide.Total manganeseIronCarbonGangue and acid insoluble•82·04%56.15%0·1405%4·82%4·848% (4,82% is car-bon which is not cOll-sidered as impuritybut has beneficial eff-ects).3·83%3·914 gms/cc.Moistureneal densitypH-En'1F RelationshipElI,=O H1-0·068 pH.AVERflGE ENERGY OONSUMED.• 0·975 Kwh per poun.l of manganese dioxide produced.Wel claim:1. A process for the electrodeposition of manganese di.oxide particularly for ~he production of battery' grademanganese dioxide from manganese ores which consists illelectrolysing manganese sulphate solution (obtained frommanganese ore) in water and wherein not less than 5 co.of nitric acid of 1·42 sp. gr. or its equivalent in IIny otherconcentration of nitrio acid is added per litre of manga-nese sulphate solution in water.2. A process 'lS claimed in Claim 1 wherein 7 to 12 OCS.of nitric acid of 1·42 specific gravity are added per litreof manganese sulpilate solution containing 150-2.'50 gramsof manganese sulphate per litre and 4 to 8 c<:s. of suI.ph uric acid of 1,84 specific gravity.3. A process as claimed in Claim 1 or 2 wherein thestarting material for the production of manganese sul-phato consists of low grade manganese ore containing highiron, silica and aluminrt contents and in "hich the per-centage of manganese Varies from 5 to 30.4. A process as claimed in any of the preceding claimswherein manganese snlpllate suited for electrolysis isobtained from the mang;anese ores by any standard proce-dure such as by roast-reduction followed by leaching witlt,cell effluent containing dilute acid and manganese s1tl-phate, and purification OR by treatment with waste pickleliquor of the iron and steel industries such as the mixtureof ferrous sulphate and dIlute sulphuric acid OR by emp-loying reducing agents such as carbon, saw dust, sulphurdioxide, iron or the like in sUlphnric acid medium.5. A proeess as elaimed in any of the preceding claimsIVherq~nelectrolysis is carried out in an electrolytic cell of\vhic;h hoth anode and cathode are of graphite.6. A process as claimed in any of the preceding claimswherein the voltage across the electrodes in close ein:uitis 1·8 to 2-2 volts.7. A process as claimed in any of the preceding claiIlU.'wherein the electrolysis is carried out in dectrolvtic cellwhich has no diaphragm. .8. A process for the electrocleposition of manganese di-oxide substantially as hereinbefore described .9. Battery grade manganese dioxide from any grademanganese ore whenever obtained according to a processsubtantially as hereinbefore described.R. BHASKAR PAl,Pafeants Officer,Council of Scienfi'fic &: Indutrial ResearchDated this 13th day of Febru.~ry 1~·58.

Improvements in or relating to production of battery grade manganese dioxide from manganese ores

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