Bolkardağı altın-gümüş-kurşun-çinko cevherlerinin değerlendirilme olanaklarının araştırılması

Abstract

Ill G Z E T Bu tez, Bolkardağ Altın-Gümüş-Kurşun-Çinko Maden Yatağındaki Yeşelli Mağarasına ait temsili numuneler üzerinde altın ve gümüşü kazanabilmek amacı ile yapılan araştırmaları ve sonuçlarını kapsamaktadır. Laboratuvar etüdleri iki ayrı numune üzerinde yürütülmüştür. * 1. `Gümüşçe Zengin` Cevher : Altın içeriği düşük, gümüş içeriği yüksek alan cevher türüdür. 2. `Altın ve Gümüşçe Zengin` Cevher : Altın ve gümüş içeriği yüksek olan cevher türüdür. Bu numuneler üzerinde mineralojik etüdler, boyut küçültme, gravite ve manyetik ayırma ile ön zenginleştirme, ayrıca siyanürle çözündürme deneyleri yapılmıştır. Temsili numuneler üzerinde yapılan mineralojik etüdler sonucunda; kıy metli mineral olarak nabit altın, nabit gümüş, jarositlere bağlı gümüş, tetra- edrit-tenantit, serüzit, anglezit, galen, plumbo-jarosit, mimetit, sfalerit, smitsonit, hidrozinkit, hemimorfit,kalkopirit, kovelin, kalkozin, malakit, gü- tit-lepidokrosit-limonit, markasit, pirit, manyetit ve gang mineralleri' olarak da kalsit, aragonit, ankerit, kuvars, psilomelan, muskovit, serisit, felds pat, kil mineralleri saptanmıştır. Ön Zenginleştirme `Gümüşçe Zengin` cevher numuneleri ile değişik boyutlarda sarsıntılı masa deneyleri yapılmış; en iyi sonuç olarak, 0.5 mm. altında, % 56.. ^9 Pb ve % 52. 6U Ag kazanma verimiyle % k&.kO Pb ve 2226 gr/t Ag içeren kurşun konsant resi elde edilmiştir. `Gümüşçe Zengin` cevherden elde edilen bulgulara dayanılarak, boyutu 0.5 mm. altında olan `Altın ve Gümüşçe Zengin` cevhere de sarsıntılı masa ile zenginleştirme uygulanmıştır. Deneyler sonucunda; % 36.67 Pb, % ^+^.08 Au, % 23.27 Ag kazanma verimiyle % 51.87 Pb, 129.9 gr/t Au, 1960 gr/t Ag içeren kurşun konsantresi elde edilmiştir.IV `Gümüşçe Zengin` cevher ile bu cevherden elde edilen sarsıntılı masa konsantre ve araürunieri üzerinde yüksek alan şiddetli, manyetik ayırma deney leri yapılmıştır. Manyetik ayırma ile, sarsıntılı masa konsantrelerindeki kur şun içeriklerinin % 90'ın üzerinde metal kazanma verimi yle % 50'nin üzerine çıkabileceği anlaşılmış; araürünlerde ise, % 60 metal kazanma verimiyle % 24-31 Zn içeriği olan konsantreler elde edilmiştir. Değişik boyutların altındaki tuvenan cevher numuneleri üzerinde yapılan manyetik ayırma deneyleri sonucunda; % 75-80 Pb, % 70-72 Ag ve % 65-70 Zn ka zanma verimleri ile % 15 Pb, 700 gr/t Ag ve 19.7 Zn içerikleri olan konsantre ler elde edilmiştir* Siyanürle Çözündürme Her iki cevherin tuvenanları ile ön zenginleştirme artıklarında çözün dürme deneyleri yapılmıştır. Deneylerde; KCN konsantrasyonu, koruyucu alkali miktarı, katı/sıvı oranı, tane boyutu, pülp sıcaklığı ve çözelti değişiminin siyanürle çözündürmeye etkileri araştırılmıştır. `Gümüşçe Zengin` cevherle yapılan doğrudan siyanürle çözündürme deney leri, çinko varlığının KCN ve CaO tüketimini arttırdığını ortaya koyduğundan, hem tuvenan cevherdeki hem de sarsıntılı masa +. manyetik ayırma artığındaki çinko, HpSO, ile uzaklaştırıldıktan sonra siyanürle çözündürme deneyleri ya pılmıştır. Tuvenan cevherle yapılan deneyler sonucunda elde edilen en iyi çö zündürme koşullarında, % 88.15 Au ve % 83.25 Ag çözünme verimi elde edilmiş ve çözündürme sonucunda, KCN ve CaO tüketimleri 5.37 kg/t ve 28.90 kg/t olmuş tur. Sarsıntılı masa + manyetik ayırma artığında ise % 80.16 Au ve % 72.62 Ag çözünme verimi elde edilmiş; KCN tüketimi 2.46 kg/t, CaO tüketimi de 24.60 kg/t olmuştur. `Altın ve Gümüşçe Zengin` cevherin çinko içeriği düşük olduğundan doğ rudan siyanürle çözündürme deneyleri yapılmıştır. Tuvenan cevherle yapılan çö zündürme deneyleri sonucunda; % 89.50 Au ile % 68.92 Ag çözünme verimi elde edilmiş ve KCN tüketimi 2.25 kg/t, CaO tüketimi 18.20 kg/t olmuştur. Sarsıntı lı masa artığında ise % 84.23 Au ile % 60.29 Ag çözünme verimi elde edilmiş ve KCN tüketimi 2.29 kg/t, CaO tüketimi 18.45 kg/t olmuştur.Yapılan araştırmalar sonucunda, her iki cevher türünde de en yüksek me tal kazanma verimlerine, ön zenginleştirme + siyanürle çözündürme uygulanması ile ulaşılabileceği anlaşılmıştır.

VI SUMMARY The thesis presented here is the results of verious labo ratory investigations carried upon two different representative samples of Bolkardağ Gold-Silver-Lead-Zinc Ore taken from Yeşelli Mağara. After the preliminary analysis, it has been found that one of the samples has 1.1 gr/t Au, 380 gr/t Ag, 7.71 % Pb, 12.56 % Zn; the second one has 1^.5 gr/t Au, U15 gr/t Ag, 7,03 % Pb and 2.75 % Zn so that, they are named as `ore of lower gold and higher silver` and as `ore of higher gold and silver` respestively. Various size reduction techniques, pre-concentration tests by gravity and magnetic separation and cyanidation tests mere applied on the samples during the laboratory work and their mine- ralogical composition- were stutied by various optical means, x-ray dif ractometry and electron microscopy. Mineralogical studies revealed that, the valuable minerals such as native gold, native silver, jarositic silver, tetrahed- rite-tenantite, galena, cerussite, anglesite, plumbo- jarosite, sfhalerite, simthsonite, hydrozincite, hemimorphi te, pyrite. n?- ethite-lepidocrosite-limonite, marcasite, arsenopyrite, magneti te, chalcopyrite, covellite, chalcocite, malachite and gang mine rals such as calcitp, quartz, aragonite, ankerite, psilomelane, muscovite, sericite, feldspar, clay minerals are presented in the samples. The major part of the silver is related to tetrahedrite in `ore of louer gold and higher silver` and this mineral is distributed as small graines in galena phase. Silver minerals of the second ore, however, are principally in the form of nati ve and jarositic silver. Gold minerals observed in this ore are also in the form of native gold of free particles 0.1-0.2 mm. diameter in size.vır Benefication By Tabling After reducing the size of are under 1 mm., G.5 mm. and 0.3 mm., the concentration tests were carried out on `ore of lo wer gold and higher silver` by means of laboratory Wilfley table, The tests yielded that the sample of particle size under 1 mm. has lead concentrate of 40.20 % Pb and 1857 gr/t Ag uith a reco very of 56.92 % Pb and 53.34 % Ag; the sample of particle size under 0.5 mm. has lead concentrate of 48.40 % Pb and 2226 gr/t Ag uith a recovery of 56.49 % Pb and 52.64 % Ag and the sample of particle size under 0.3 mm. has lead concentrate of 54.70 % Pb and 2428 gr/t Ag uith a recovery of 55.27 % Pb and 49.76 % Ag. The tabling tests of `ore of higher gold and silver` of size under 0.5 mm., however, yielded a lead concentrate of 51.87 % Pb, 129.9 gr/t Au, 1960 gr/t Ag uith a recovery Of 36.67 % Pb, 44.08 % Au and 23.27 % Ag. Benefication By Magnetic Separation Table middlings, concentrates and rau ore of `ore of lo wer gold and higher silver` have been subjected to various mag netic separation tests in order to concentrate the metals of the ore by means of high intensity, dry magnetic separation. Le ad content of table concentrates were increased to over 50 % with a recovery over 90 % ; the zinc contents of table middlings were increased to 24-31 % Zn with a recovery of 60 % Zn. Bulk concentrates uith 15 % Pb, 700 gr/t Ag, 19.7 % Zn and at recoveries of 75-80 % Pb, 70-72 % Ag and 65-70 % Zn were obtained, after the tests carried on the rau ore of sizes under 1 mm., 0.5 mm. an d '0.3 mm.Will Cyanidatian The cyanidatian tests were carried an the rau ores and '`airings Df pie-concentration in order to recover gold and silver. The ef': >c s of the KCN concentration, the amount of protec tive alkalinity, pulp density, particle size, pulp temperature and optimum cyanidation conditions of rau ores (`ore of lower gold and higher silver` and `ore of higher gold and silver`) were in vestigated. The effect of particle size yas only tested on the pre-concentration tailings. High amount of KCN and CaO were consumed when the direct cyanidation was applied to `ore of lower gold and higher silver`. The oxidized zinc minerals were removed from both the raw ore and tailing of pre-concentration by H`S0, leaching in order to elimi nate zinc. The cyanidation conditions were investigated in detail after the removal of zinc by H`SQ, leaching from the raw ore of lower gold and higher silver. The optimum cyanidation was obtained in the following conditions: KCN concentration Protective alkalinity Pulp density Particle size PüId temperature Leaching time Change of solution 0.3 % 0.G6 % CaO 17 % solid minus 0. 075 mm. 20 ; 2DC 56 hours 1/2 volume in first hour Ths leaching recovery was 88.15 % Au and 83.25 % Ag in optimum.' cyor.idation; 5.37 kg/t KCN and 28.90 kg/t CaO were consu mer] at the end of the cyanidation. The pregnant solution contai ned 0.17 gr/t gold, 5ft. 83 gr/t silver, 14^.9 gr/t zinc, 290.3 gr/t lead, 9.3 gr/t copper.IX The optimum cyanidatİDn was determined after the removal of zinc by H`S0, leaching from the tailing of pre-concentration in the following conditions: KCIM concentration Protective alkalinity Pulp density Particle size Pulp temperature Leaching time 0.3 % 0.06 % CaO 17 % solid minus 0.106 mm. 20 + 2DC 48 hours Leaching recovery uas 80.16 % Au and 72.62 % Ag in the op timum cyanidation; 2.46 kg/t KCIM and 24.60 kg/t CaO were consumed at the end of the cyanidation. The pregnant solution also contai ned 0.13 gr/t gold, 37.91 gr/t silver, 238.1 gr/t zinc, 5.9 gr/t lead and 1.2 gr/t copper. The highes metal recoveries were obtained by means of pre-concentration + cyanidation on `ore of lower gold and higher silver`. 53.40 % of lead, 41.64 % of gold and 50.20 % Df silver were recovered by 'tabling + magnetic separation and 46.78 % of gold and 30.16 % of silver were leached by cyanidation. Since the ore contains little amount of zinc, the cyanida tion tests were carried out directly in `ore of higher gold and silver`. The following optimum conditions were obtained in the raw ore by means of cyanidation tests: KCIM concentration Protective alkalinity Pulp density Particle size Pulp temperature Leaching time 0.2 % 0.02 % CaO 17 % solid minus 0.106 mm. 20 + 2DC 32 hoursLeaching recovery was 89.50 % Au and 68.92 % Ag in the optimum conditions; 2.25 kg/t KCN and 18.20 kg/t CaO were consu med at the end of the cyanidation. The pregnant solution contai ned 2.60 gr/t gold, 57.20 gr/t silver, 427.9 gr/t zinc and 10.30 gr/t copper. Cyanidation was also applied to tailing of tabling and the optimum cyanidation was determined in following conditions: KCN concentration Protective alkalinity Pulp density Particle size Pulp temperature Leaching time 0.2 % 0.02 % CaO 17 % solid minus 0.106 mm, 20 + 2DC 32 hours Leaching recovery was 84.23 % Au and 60.29 % Ag in the optimum cyanidation; 2.29 kg/t KCN and 18.45 kg/t CaO were con sumed at the end of the cyanidation and the pregnant solution contained 1.43 gr/t gold, 40.39 gr/t silver, 261.2 gr/t zinc and 11.3 gr/t copper. The highest metal recoveries were obtained by means the pre-concentration + cyanidation on `ore of higher gold and sil ver`. 36.67 % of lead, 44.08 % of gold and 23.27 % of silver were recovered by tabling and 47.10 % of gold and 46.26 % of sil ver were leached by cyanidation.