Balıkesir-Balya yöresi kurşun-çinko tesis artıklarının değerlendirilmesi
Beneficiation of Balya lead and zinc tailings
Yazar: GÜLAY BULUT
Danışman: PROF.DR. M. ZEKİ DOĞAN
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü
Derece: Yüksek Lisans, 1991
Konu: Maden Mühendisliği ve Madencilik = Mining Engineering and Mining
Dizin: Atıklar = Wastes ; Balıkesir-Balya = Balıkesir-Balya ; Flotasyon = Flotation ; Kurşun = Lead ; Çinko = Zinc

Özet:
ÖZEI Balıkesir -Balya yöresinde bulunan eski simli kurşun madeninin zenginleştirme tesisi artıklarının değer lendirilebilme olanaklarının araştırılması bu tezin konusunu oluşturmaktadır. Bölgede Flotasyon Artığı, Jig Artığı, Ocak Yolu Altı Jig Artığı ve İzabe Artığı olmak üzere dört çeşit yığın bulunmaktadır. Bölgeden alınan bu dört çeşit artık numuneleri üzerinde boyut dağılımı analizi ve mineralojik incelemeler yapılmıştır. Bu incelemeler sonucunda izabe artığının farklı özellikler taşıdığı saptandığından, bu tezin konusu dışında tutulmuştur. îlk üç artık yığınından alınan temsili örneklerin miktarı oranında karıştırılması ile hazırlanan numune üzerinde zengin leştirme deneyleri yapılmıştır. Artıklarda yapılan minerolojik incelemelerde, pirit, sfalerit, seruzit, galen, eser miktarda kalkopirit ve arsenopirit, kuvars, kalsit, feldspat gibi minerallere rastlanmıştır. Metal sülfürler uzun süre atmosferik koşullar altında kaldığından kenarlarında ayrışım zonları oluşmuştur. Galen genellikle çok ince dağılımlı olup, kenarlarında alterasyon sonucu oluşan seruzit tabakası ve tayin edilemeyen kurşun oksit bileşikleri gözlenmektedir. Karışım numunesinin yapılan boyut dağılımı analizlerinde ince boyutlu olup, % 45' e yakın bir kısmının 0.074 mm altında bulunduğu sap tanmıştır. Yine yapılan kimya analizlerinde numunenin % 4.7 Zn ve % 3.8 Pb içerdiği anlaşılmıştır. Karışım numunesiyle ön zenginleştirme amacıyla, sarsıntılı ma sada, malzemenin yaklaşık % 45'ni oluşturan şlam ayrıldıktan sonra, çeşitli boyut gruplarında deneyler yapılmıştır. Uygun verimlerle, bir kurşun ön konsantresi alınamamıştır. Flotasyon deneylerinde, ksantatlarla çeşitli koşullarda öncelik le balk konsantre alınmaya çalışılmıştır. Yapılan ön deneylerde en iyi sonucu pH 12' de 400 g: /ton CuSO, ve 250 g /ton KEX+KAX karışımı kulla narak ulaşılmıştır. % 36 Zn ve % 9.02 Pb içeren konsantre, % 40 gibi bir metal kazanma verimiyle elde edilmiştir. Flotasyonda ikinci grup deneylerde çinko-kurşun minerallerine karşı seçimli, Cyanamid firması tarafından önerilen fosfin tipi ve thiofosfat tipi reaktifler denenmiş tir. En iyi sonuç Aero 3477 isimli reaktifle alınmıştır. Burada % 48.94 Zn ve % 11.18 Pb içeren konsantre, % 40, gibi bir metal kazanma verimiyle alınabilmiştir. -ıı-

Abstract:
BENEFICIATION OF BALXA LEAD AND ZINC TAILINGS SUMMARY Increasing need for metal, exhaustion of rich ore bodies necessitate explotation of poor and complex ores. There are lead-zinc tailings which have one million tonnes reserve in Balya-Balxkesir region, which require an immediate attention. Utilization of such an important row-material is expected to contribute to the national economy of our country. Silver containing lead-zinc mine in the vicinity of Balya- Balikesir was exploited by a French company in the years of 1880 to 1935. After the French company stopped the activities, this mine was exploited by a number of Turkish companies. Presently, there are a number of tailings (Jig and Flotation) and slag pile in the mine area, which require further evaluation. The evaluation of these tailings had been the subject of this thesis. The sample used in this study comprises flotation tailing'is, jig tailings, jig tailings of lower mine road and slag. Sytematic samples by drilling are obtained by a grid on jig and flotation tailings. On the other hand, channel sampling was done on lower mine road tailings and slag pile. Samples obtained from different piles were blended as a final step for the preparation of the representative samples for the tests. The tonnage and assays of tailings are shown in Table 1. Table 1. Tonnage and Assays of Tailings and Slags Ore Piles Flotation Tailings Jig Tailings Lower Mine Road Tailings Slags 300 9.90 3.25 0.22 48 TOTAL 1000 5.90 3.50 0.15 55 0.26 -xix-Mineralogical studies were done on tailings and it was shown that similar minerals were present in each tailings piles, namely, sulphide and gangue minerals. The former consisted of pyrite, sphalerite was mostly liberated or locked with pyrite and chalcopyrite. Pyrites are unoxidized and usually free, very little amount of galena was observed with alteration zones on the surface. Galena occurs in fine dipersion and highly oxidized state where cerusite and anglesite are encountered. Chalcopyrite was finely dispersed in sphalerite. As tailings except slags, had similar chemical composition the combined sample was prepared, according to the three tailings piles for the concentration tests by blending the lots taken from three tailings samples. The portion taken from flotation tailings formed 65 % of the combined sample. The combined sample contains a large proportion of pyrite and shows a high degree of oxidation which has 4.7 % Zn, 3.8 % Pb and 0.12 % Cu in a very fine form nearly 50 % in 75 Mm. We can say that combined sample, which is produced by blending these three tailings, contains about 20 % Quartz, 18% calcite, 10 % Feldspar, 30 % Pyrite and 12 % Lead-zinc minerals. After determining ". properties of the combined sample, concentration tests were executed in order to produce first a pre- concentrate by gravity concentration on shaking tables. The concentration was done on two fractions, namely, -1 + 0.3 mm and -0.3 after desliming. Then it was possible to discard some material as table tailings with a loss of 25 % Zn and 10 % Pb. When this per-concentrate was retreated by tabling, a concentrate having 33 % Pb was obtained with a very low recovery such as 8.4 %. As it was not possible to produce a concentrate with a high recovery by gravity concentration flotation tests were performed. In preliminary flotation test, the parameters such acs ore size, collector kind and dosage, pH, KCN, K^Cr^Oy, CuSO, and Na2S were investigated. First, it was tried to produce Dulk concentrate 'By preliminary tests. The results of preliminary flotation tests revealed the following: 1. Flotation experiments conducted as a function of grinding time yielded an optimum of 5.5 minutes in which the majority of the material passed through 0.1 mm. This material has been used throughout this investigation. IV2. Stage addition of 250 g/t K-ethyl xhantate and K-amyl xanthate at 1/1 ratio represented the optimum collector concentration in sulfide flotation. It was found that the addition of xanthates in one stage lowered the recoveries. 3. Pyrite has been depressed by KCN at a concentration range of 25-75 g/t and pH= 8.5 with little success. However, at high pH values, depending on the CN concentration, the zinc minerals were depressed. Further tests with cyanide indicated no significant improvement in recoveries. 4. Activation of +sphalerite in flotation is only possible by such ions as Cu or Pb. The tests carried out at pH= 8 had a limited effect due to the presence of other metal ions which concurrently activated pyrite. As pH was increased, precipitaiton of metal ions in the form of hydroxides accomplish both depression of pyrite and activation of sphalerite by CuSO,. The CuSO, concentration of 400 g/t was found to be sufficient for activation of zinc ions. When the concentration of CuSO. was increased from 400 g/t to 800 g/t, no significant improvement in recoveries was obtained. Thus, the concentration of CuSO, was maintained at 400 g/t throughout this investigation. 5. The combined (blended) sample used in the mineralogical investigations revealed, in addition to galena and sphalerite, the presence of Ceruzite and in large amounts unidentified lead oxide minerals. Sulfidization tests were not much succesful in upgrading the recovery of Pb and further incease of Na2S concentraiton led to the depression of zinc itself. The sulfidization tests were carried out by means of Na2S which induces S ions on the surface of oxide minerals such as lead ana zinc. Conversion of oxide minerals in to sulfide type by Na2S is commonly practiced in industry. However, in the case of Balya tailings which have gone through a prolonged exposure to atmospheric conditions, the surface of the minerals is severely oxidized. Thus, the possibilty of exchange of oxygen with sulfur is consderably reduced. It may be possible to -conduct _ exoerimenta irnder the incipient concentration of Na2S at which lead can be selectively separated from zinc. 6. The effect of pH was investigated at other parametres being constant. In these tests, as the pH was increased, the grade of zinc was found to increase. The concentrates at pH values of 11 of 12.5 cleaned twice and collector concentration of 250 g/t K-Ethyl Xanthate+ K-Amyl Xanthate resulted in metal contents of 36.03 % Zn and 9.02 % Pb with recoveries of 40 %. This concentrate is a reasonably suitable feed material for Imperial Smelting Process.7. Experiments conduted with xanthate aimed to recover a mixed concentrate of lead and zinc. While zinc produced acceptable recoveries, lead did not yield saticfactory recoveries. For this reason, a concentrate suitable for Wealz Process assaying a minimum of 20 % Zn and a maximum of 5 % Pb has been tareated through use of potassium bichromate. But a limited success was achieved due to the very fine distribution of lead in unliberated form. The laboratory scale flotation tests were extended to pilot scale flotation tests. The sample used in both phases of the study had the same composition. Both tests were found to correlate very well. The sample subjected to flotation tests assayed 3.00 % Zn and 3.19 % Pb. The screen analysis indicates that 55 % of the partictes. were below 38 Mm; 84 % of the zinc and 89 % of the Pb remains in this subsieve size fraction. İt is this liberation characteristics of the material that creates problems with conventional beneficiation techniques. In order to better characterize the valuable and gangue minerals in the sample a systematic mineralogical analysis was carried out. In thin and polished sections, the plus 38 /1m size fraction was subjected to identification tests through mineralogical analysis. In polished section, pyrite is observed as the main mineral while sphalerite is found seldom; the center opaque and the sides decomposed Galena is also seldomly found in the form fines with sides grooved. Quartz is observed as the main mineral in the thin section. Feldspar on the other hand, is observed infrequently. Since the mineralogical investigations revealed that about 80 % of the zinc and lead minerals are concentrated below 38 ^m, leaching tests were carried out in this size fraction with the aim of recovering lead and zinc. Leaching experiments were performed with nitric and acetic acid combinations. The best results were obtained when this combination was at 1/1 rai to and room temperature. As a result, 9.05 % Zn and 64 % Pb were taken into the solution. An attempt was then made to recover the zinc remained in the solid (undissolved partion of the ore) by using reagents recommended for oxidized zinc flotation, Amine 3389 Hoe and Amine 2835. Hoe manufactured by Hoechst. Prior to this operation, the zinc metal was recovered by Aero 3477 reagent with an assay of 50.18 % Zn and a metal recovery of 34.8 %. The middlings and tailings were then combined to carry out zinc flotation by amine but the results were not satisfactory possibly due to the presence of zinc accumulated in the slimes. VIThe explotation of Balıkesir Balya tailing represents no difficulty in terms of costs incurred in mining and comminution, it experiences technical dificulties in the beneficiation process due to long exposure of mineral surfaces to atmospheric oxidation. To overcome this problem of oxidation and also to achieve a liberated material, very fine grinding is required. Technologies for treatment of fines such as column flotation however are in the procss of development. Within the context of this thesis concentrates suitable for Waelz and Imperial Smelting Processes have been obtained. Since the recovery of zinc and lead minerals requires very fine grinding for liberation, it necessitates use of new flotation technologies such as column and jet flotation and also an ingenius reagent strategy. Vll