US1091545A - Recovery of nickel from its ores. - Google Patents
Recovery of nickel from its ores. Download PDFInfo
- Publication number
- US1091545A US1091545A US75867713A US1913758677A US1091545A US 1091545 A US1091545 A US 1091545A US 75867713 A US75867713 A US 75867713A US 1913758677 A US1913758677 A US 1913758677A US 1091545 A US1091545 A US 1091545A
- Authority
- US
- United States
- Prior art keywords
- nickel
- ores
- metals
- ore
- solution
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 title description 79
- 229910052759 nickel Inorganic materials 0.000 title description 39
- 238000011084 recovery Methods 0.000 title description 2
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 16
- 229910052751 metal Inorganic materials 0.000 description 16
- 239000002184 metal Substances 0.000 description 16
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 14
- 239000000243 solution Substances 0.000 description 14
- 150000002739 metals Chemical class 0.000 description 12
- 238000000034 method Methods 0.000 description 9
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 8
- 239000002253 acid Substances 0.000 description 8
- 239000000395 magnesium oxide Substances 0.000 description 8
- 239000002904 solvent Substances 0.000 description 8
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 7
- 229910052500 inorganic mineral Inorganic materials 0.000 description 7
- 229910052749 magnesium Inorganic materials 0.000 description 7
- 239000011777 magnesium Substances 0.000 description 7
- 239000011707 mineral Substances 0.000 description 7
- 235000010755 mineral Nutrition 0.000 description 7
- 230000001376 precipitating effect Effects 0.000 description 6
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- 241000282320 Panthera leo Species 0.000 description 4
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 150000003839 salts Chemical class 0.000 description 4
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 238000000605 extraction Methods 0.000 description 3
- 150000002500 ions Chemical class 0.000 description 3
- 150000002681 magnesium compounds Chemical class 0.000 description 3
- LGQLOGILCSXPEA-UHFFFAOYSA-L nickel sulfate Chemical compound [Ni+2].[O-]S([O-])(=O)=O LGQLOGILCSXPEA-UHFFFAOYSA-L 0.000 description 3
- 229910000363 nickel(II) sulfate Inorganic materials 0.000 description 3
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 2
- 235000011941 Tilia x europaea Nutrition 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 229910000019 calcium carbonate Inorganic materials 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 239000004571 lime Substances 0.000 description 2
- 238000005065 mining Methods 0.000 description 2
- 101100181929 Caenorhabditis elegans lin-3 gene Proteins 0.000 description 1
- 101100456896 Drosophila melanogaster metl gene Proteins 0.000 description 1
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 1
- 101100270435 Mus musculus Arhgef12 gene Proteins 0.000 description 1
- 244000141353 Prunus domestica Species 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- 240000008042 Zea mays Species 0.000 description 1
- 235000005824 Zea mays ssp. parviglumis Nutrition 0.000 description 1
- 235000002017 Zea mays subsp mays Nutrition 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- WYTGDNHDOZPMIW-RCBQFDQVSA-N alstonine Natural products C1=CC2=C3C=CC=CC3=NC2=C2N1C[C@H]1[C@H](C)OC=C(C(=O)OC)[C@H]1C2 WYTGDNHDOZPMIW-RCBQFDQVSA-N 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 235000005822 corn Nutrition 0.000 description 1
- 239000011790 ferrous sulphate Substances 0.000 description 1
- 235000003891 ferrous sulphate Nutrition 0.000 description 1
- 239000000706 filtrate Substances 0.000 description 1
- 101150008103 hal gene Proteins 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 1
- 229910000359 iron(II) sulfate Inorganic materials 0.000 description 1
- 239000008267 milk Substances 0.000 description 1
- 210000004080 milk Anatomy 0.000 description 1
- 235000013336 milk Nutrition 0.000 description 1
- 101150006061 neur gene Proteins 0.000 description 1
- SPIFDSWFDKNERT-UHFFFAOYSA-N nickel;hydrate Chemical compound O.[Ni] SPIFDSWFDKNERT-UHFFFAOYSA-N 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- SYOKIDBDQMKNDQ-XWTIBIIYSA-N vildagliptin Chemical compound C1C(O)(C2)CC(C3)CC1CC32NCC(=O)N1CCC[C@H]1C#N SYOKIDBDQMKNDQ-XWTIBIIYSA-N 0.000 description 1
- 238000010792 warming Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G49/00—Compounds of iron
- C01G49/14—Sulfates
Definitions
- Patented Main 31, 193.4.
- This extraction prunes is designed mainly to recover sulisliintinl pirupnrliuns nl nickel from guiudge-il'e ores whivh are too pour in lzmi'l the (0st nl ezu'i'iuge for treatmentat a place other than that at u'hieh lhe ore is mined: nurl involves a supply nil sulfuric acid which may be suitably' nmnufmttured at ()J neur the mines 01- mm be imported from n mmiulneiuring; Center 110% too distant theieli'i-om.
- magnesia jt'ccovei'ctl for re-use well-inixmjl mass to stand in 21 SL1ll'illJl-i3 tank by i'irystullizing a milk .i ll' quantity of mag- Oi vat for a period of'an hour l two, and nesiuin sulfate from til solution and calcin- "then heat by steam, or on a suitably heats-ii ins it on a nnace-heswii antl'ralilfling in a furnace-hearth, until the temperature of the suil'icicncy of c: i'lion.
- the .iiixtui'c has been contacl with metallic ii'ou ('llll'lll J tion process, as of course :j' or no ferrous iron.
- vuuawhut Elli swipes may lie l0 1 metals other than magnesium and nickel and precipitating the nickel from the remaining ing the ore with a'mineral acid in such nickel uantity as to act as a selective solvent of t e nickel over the magnesium compounds formingthe ganguc salts of nickel and other metals by means of magnesla.
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Manufacture And Refinement Of Metals (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Silicates, Zeolites, And Molecular Sieves (AREA)
Description
STONE SULMAN AND IIUGH FITZALIS KER GLAND, ASSIGNORS TO THE -L'iDAGASCAR MINERALS:
ATRICK PIGARD, OF SYNDICATE RECGVERY OF NICKEL FROM ITS GEES.
him-1,5 25
No Drawing To aZZ 'lr/jmm h may; my: m:
Be it knnwn lhnt we, HENRY LITINGSTONE Semun and HUGH FI'FZALIS KIRKPATRICK Plenum "nhjeeis of the Linenf England, and rel in m'nlnn, En zunl have invented certain new uiul imelul linpruvements in. the Reamer of Nickel from its Ores, of which lhe follnwing n speciliezv i ten to ii'npi' wmnnts in the i'ecovei-y f Ill? :l from its silicate ores and prii'iiirulziil from gnrnierite fires in which this uwtnl UL' flll'b' as n double silicate of nickel and nineuwin. Gzn'niei'ile usually occurs in u innii'ii; ur serpentine, with mug} nesinqnieuj zlilkl with other hyih'nleil silicieus inne nesiuin nnneinla which it closely approaches in uiieeilie grnvily and in e emin other physnul ii'nel' 1'.-;; this similarity l'LhLlOIS enlinnr inel'hmls fur {he concenli'uiien the gin-n zi-iie l'i'uin. lhese ores ineil'eclivi;
Anew-(ling to this invention ii. preeess for the extme'iinn nii-kel l'inin garnierile L'UlCl like sihiale ores wtnnpi'iai the treatment of the on: with n mini-ml lllflkl in s-tnch :1 quanlilgv a in nu n5 :1 eleetive solvent of the nickel.
As well knwa'n huth qninieiite :inel ifs nuilrix flecemgi metl hy mineral eius,
have 'Fnunu. however, that by using" :2 nun-h nnnller quantity uf' acid a i in of the nickel can be n: Qnlilltl'llt ores even inngnesizi mineral: being nelceiil, but to :1. degree Lin-3 former C2198. In any sin is dislie much less hum. in emu-l l Specification of Letters Patent.
Application filed April 3, 1913.
Patented Main, 31, 193.4.
Sc1ialN0.758.67/.
pnniQ-fl hy an excessive break up of other magneniu IfllIlCirilS Willi :1 co'i'resplunlingly heavy loss of acid.
This extraction prunes: is designed mainly to recover sulisliintinl pirupnrliuns nl nickel from guiniei-il'e ores whivh are too pour in lzmi'l the (0st nl ezu'i'iuge for treatmentat a place other than that at u'hieh lhe ore is mined: nurl involves a supply nil sulfuric acid which may be suitably' nmnufmttured at ()J neur the mines 01- mm be imported from n mmiulneiuring; Center 110% too distant theieli'i-om. F0; example we have obtained an ext-ractien of Over (3', ml? the valuable metal from n glllillol'lii (we (nulnining two per (rent. of nickel. :uul :1 recovery of n urly 60f; 'lii'im'i gnrnie lie urn 'l'z-m'u another source, which emil nineil Bi f pol nickel. with the same amount of ueiil in en h ease: viz I" n qu-iulity of ,il'rurie :uhl nmnunling to of l'he Weight ol? the we. liming reui'il tn the lueul e 'unlilinn eneh of these exlifnelions nhmveii n suhid uni'iul eennnmical rvauliz, ihnt in tin: (use mi The rh'hei' ore being the mute ni'efiluhle uuiwillinl'nniling lho lesser ITQCU'VPY). :eiiher operntii'in. would have been cmnmeifeirill @uccesnful sueh '-mi(liliiniis l'he zu-iil emisuuipl'ion involved would mnounl to uhuul' R07 01 the wife weight. It X51 nl'u'inm l'invvi'eveil'hnl: i'hrhei' QPJnlGll'CG ores will. he uhle in eluml a greater nehl ('nnsumplinn emit lhnn poei'ei- OILF', nml We therefore (l0 not mnfine (nu-- selves in any ileliniln wimunpiinn m' sie i'l as This will he i'ee ulnteil l v the eenumnie eon ilitinns pertainingi0 eneh we.
Our niel'hml is thus based upon a selective i'lisisoluiiion nelion which eei'inin mineral :u-iils exei'i upon :1 mixluie of nicknldnug neuizx and magnesium nilienl en within certain eenmunienl limiia which will he determined in each (use l) the peeuliur nature of the mixed miuerzils'- lheii spieilie behavior to mills. and by the eeoumuie 'l uetuw available at the milieu. "0 have also found lhnl l'he hydrated silicuie of magnesia. e'te. which are #Ontuinefl in larg pi'n im'l'iun in low le- Q'zlllllillid on: HlHlLI'Q'O i'uniil, weathm' elmug'e when eYUmeil in air. espe- E emulilinu This weathi z n n'i-u'n'iug snluhility nninieuurls in acid, that in :1 ei'unh vl Y action 7'- ll:
' screen mesh of from to per linear inch moro'of salt in a first extra I next and succcssiuo quantities of 1 is to say in :11 increased coiuninniition voi} ll l'he solutions olitaiucil by the treatment 1 acid relatively to the nickel dissolved. of the ores with sulfuric acid colilaln iron as A feature of this invention therel'orc con ferrous sulfate, it may be oxidized to ferric sists in applying acids iothe ore in a freshly su fate. by suitable eliminate or ii-clilo mined and non-weatherec condition directly note. 'lncn ponderedcarbonate of lime is it has been suitably crushed. The cl rec of ltin'evl into the Still lion whereby any iece crushing will Vary with different ores, but a. ulfuric acicl existin is noun lizccl l all roiuium sells pre- Will generally be foui'ujl suitable. u We find oipil'ctetl togetlioc w i l sulfate oi" li lcgantl no increased selective action of the acid solthe pure nickel and magnesium solution is vent, in favor of nickel, with ery finely pulfiltered therefrom. The, resulting product VGllZQCl ore material. a purified solution of sulfates of nickel anal The solvents We Q111Pl"'* tu or ma Theni' tel precipitatedfsoin hydrochloric acicls, or lllLllJlll'G-S o l 1 lion by stirriil in powrlci'ecl mag- F01 example, we may acl-rl u cei'l'ain pm )0 nos a lgG) and the pi'ecii ion may he tion of salt to the sulfuric acid, or spent liqaidecby Warming the solo. .a ad by zulijl uoi's containi n'n-it'neiium 'rli .l'iil, 'oc magnesia a little at a lime with corn We may use 2 i slantstir in order to a oid Ci'll l ylllg (lou'n magnesia with tli nickel hydrate orehe reaction s rcg'nesenteclby the the spent-liquors containing ilie equivalent of logos-slum or ,alcium chloric on .tlze
1 no; {iuili oi-ri e and l fe find the best results are olil'aiuulile all {he i will comain 'son'ie so keeping the proportion of Water in l say sufficient (in admixture with u l hut: on. heating lo (lull redness to to give a move oi less thick paste with me dehycra'te it u powdered iii 1 oxicl is prooi-o, or the 016 may ie llllXC-Ll un'ev 1 with (lucecl cari'yu from '50 to of nickel concentrated sulfunc ocicl; We allow the (Ni). The magnesia jt'ccovei'ctl for re-use well-inixmjl mass to stand in 21 SL1ll'illJl-i3 tank by i'irystullizing a milk .i ll' quantity of mag- Oi vat for a period of'an hour l two, and nesiuin sulfate from til solution and calcin- "then heat by steam, or on a suitably heats-ii ins it on a nnace-heswii antl'ralilfling in a furnace-hearth, until the temperature of the suil'icicncy of c: i'lion. The changes taking Whole is 1'?" 36d to from about 190 to 130 (I. place are represented li y ihe following equa -a paste is heated a tenu'ieialulie between and 156 C. until 'hc conversuin of the filtrate. llloreov'ei' but lit-L 3 hydrate in the Thus it is a feat re of this invention that the lion: 100 crushed. o-ie iogiineix with a pit orliou of ills-infill L\'lgO+SO +C/Q.
acicl substantially as above ecilietl S'ilfl a smell promotion of Wale-i sin icient to form it is only necessary to crystallize ancl calcine enough magnesiun'i sulfate. to the amount of magnesium cl required for: prer 'ioil'al'ion. This process RFOlTlS a method of producing magnesia as additional nickel into the soluble 'sal s has been oi to the clesirccl li'ic l sii'c t secure 'Qlt is:- h i. The licl'ein described process Sill-i tecl fion I ll cxiiaction of nickel from silicate Suiinbl Y a i I mining; other metals which consists in treatand sol utioii to k mg); the ore. with a mineral acicl in such 115 SQlnbIg} quantity as to act a; a selective solvent mining f the nickel over the magnesium compounds iing the gangue mate 'ials and precipi- I toting the nickel from the solution. of the ml but little sails of nickel untl other metals. i Y in] 9. The herein clesciibecl process for the i -.;\'traclion of nickel from silicate ores conmining other metals which consists in treating; the ore with sulfuric acid in such quanii'i'y as to act select not of, the lot over the magncsr coinpoui'icls f ue incl-e1 hi e tfecti g We find gui'nici'ile ores so treated ieltl solutions which conlain nickel a slum sulfate and/oz chloritl, 1
iron. the .iiixtui'c has been contacl with metallic ii'ou ('llll'lll J tion process, as of course :j' or no ferrous iron. is lr'omnl dissolved the able basic 5 composing r cally dissolve" vuuawhut Elli swipes may lie l0 1 metals other than magnesium and nickel and precipitating the nickel from the remaining ing the ore with a'mineral acid in such nickel uantity as to act as a selective solvent of t e nickel over the magnesium compounds formingthe ganguc salts of nickel and other metals by means of magnesla.
4. The herein described process for the extraction of nickel from silicate ores containing other metals which consists in treating the ore with sulfuric acid in such quantity as to act as a selective solvent of the nickel over the magnesium compounds forming the gangue materials, extracting with water so as to obtain an aqueous solution of nickel sulfate and other metal sulfates, purifying the solution by eliminatin metals other than magnesium and nicke stirring into the purified solution powdered magnesia to precipitate the nickel as a hyicllrate and separating the precipitated hyrate.
5. The herein described process for the extraction of nickel from silicate ores 'c'on taining other inetalswhich consistsin treatwith sulfuric acid in such quantity as to act as a selective solvent of the over the magnesium ,compounds forming the gangue materials, extracting with water so as to obtain an aqueous soluing the ore materials and prccipi tating the nickel from the solution of the tion of nickel sulfate and other metal sulfates, ing-with calcium carbonate the metals other than magnesium and nickel and precipitating the nickel from the remaining solution by means of magnesia.
6. The herein described process of extract purifying the solution by precipitating nickel from silicate ores containing other metals which consists in treating the ore in a freshly crushed and non-weathered condition with a mineral acid in such quantity as to act as a selective solvent of the nickel and precipitating the nickel from the solution of the salts of nickel and other metals.
7i The herein described process of extracting nickel from silicate ores containing other metals which consists in treating the ore in a freshly crushed and non-weathered (condition with sulfuric acid in such uan- -tity as to act as a selective solvent 0 the nickel, extracting with water so as to obtain an aqueous solution of nickel sulfate and other metal sulfates, purifying the solution by precipitating with calcium carbonate the metals other than ma nesium and nickel and precipitating the solution by means of magnesia.
In testimony whereof we have signed our names to this specification in the presence nic e1 from the remaining 7
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US75867713A US1091545A (en) | 1913-04-03 | 1913-04-03 | Recovery of nickel from its ores. |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US75867713A US1091545A (en) | 1913-04-03 | 1913-04-03 | Recovery of nickel from its ores. |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US1091545A true US1091545A (en) | 1914-03-31 |
Family
ID=3159761
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US75867713A Expired - Lifetime US1091545A (en) | 1913-04-03 | 1913-04-03 | Recovery of nickel from its ores. |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US1091545A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2468103A (en) * | 1946-03-04 | 1949-04-26 | George W Pawel | Production of ferronickel |
| US2831751A (en) * | 1955-10-27 | 1958-04-22 | Joseph J Schedel | Method for recovering nickel from ores |
| US4125588A (en) * | 1977-08-01 | 1978-11-14 | The Hanna Mining Company | Nickel and magnesia recovery from laterites by low temperature self-sulfation |
| FR2689140A1 (en) * | 1992-03-06 | 1993-10-01 | Intevep Sa | Recovery of nickel@ and magnesium@ from natural substances |
-
1913
- 1913-04-03 US US75867713A patent/US1091545A/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2468103A (en) * | 1946-03-04 | 1949-04-26 | George W Pawel | Production of ferronickel |
| US2831751A (en) * | 1955-10-27 | 1958-04-22 | Joseph J Schedel | Method for recovering nickel from ores |
| US4125588A (en) * | 1977-08-01 | 1978-11-14 | The Hanna Mining Company | Nickel and magnesia recovery from laterites by low temperature self-sulfation |
| FR2689140A1 (en) * | 1992-03-06 | 1993-10-01 | Intevep Sa | Recovery of nickel@ and magnesium@ from natural substances |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US1834960A (en) | Treating zinc concentrate and plant residue | |
| US1091545A (en) | Recovery of nickel from its ores. | |
| US1598296A (en) | Electrochemical treatment of copper ores | |
| US1588806A (en) | Metallurgical process and article | |
| US2010870A (en) | Process for recovering elementary selenium | |
| US3817743A (en) | Treatment of copper iron sulfides to form x-bornite | |
| US2823113A (en) | Process of treating vanadium and molybdenum ores | |
| US1636296A (en) | Process of oxidizing ferrous sulphate in solution | |
| US2539823A (en) | Manganese ore treatment | |
| US1011562A (en) | Method of treating copper-bearing substances. | |
| US466495A (en) | Schmidt | |
| US1496004A (en) | Process of preparing pure zinc-sulphate solutions | |
| US1023964A (en) | Preparation of zincate solutions. | |
| US1312668A (en) | Raymond f | |
| US1798255A (en) | Copper-extraction process | |
| US1111874A (en) | Process for the treatment of copper ores and the recovery of their values. | |
| US634751A (en) | Method of refining cupric-sulfate solutions. | |
| US718554A (en) | Method of extracting zinc. | |
| US954264A (en) | Treating arsenid ores. | |
| US1193734A (en) | s paec | |
| US1360271A (en) | Process of extracting bismuth | |
| US1886162A (en) | Process of treating sulphide ores of zinc | |
| US656497A (en) | Process of treating zinc-bearing complex ores for recovery of zinc or other metals therefrom. | |
| US227902A (en) | Extracting copper from ores | |
| US3841864A (en) | Method for producing nickel by segregation of nickel oxide ores |