Team Number : E41ANALYSIS OF GANGUE MINERAL ON DEPOSITS METAL TOWARDSINDUSTRIAL MINERAL AND MATERIAL PROCESSINGImam Fuad WahyudiantoChemistry Department, Universitas Gadjah Mada, Yogyakarta, Indonesia.Sekip Utara BLS 21, Yogyakarta 55281, Telp. ( 0274 ) 545188 Fax. ( 0274 ) 545188Email : Imamfuad@rocketmail.comABSTRACT Gangue minerals have many effect in ore metals and mining, the examples is in kaolin and kuarsa in Bangka Belitung, effect in separation ore nickel and hydrophobic at recovery gold using ores obtained from the active small scale gold mining sites in southeast asia.The effects of silica gangue and high sulphide gangue on gold attachment were examined including the effect of surface activators (potassium amyl xanthate) and the possibility of depressing the effects of gangue using reagents. The results of separation nickel showed an overall upgrade of Ni from 0.4 to 0.7% Ni in the flotation feed sample, at a recovery of 87% and from recovery gold showed there was no change in gold recoveries when the amount of oxide gangue (quartz) in the ore was increased, indicating absence of competition between gold and quartz gangue. High sulphide contents in the ore above 6% reduced gold recoveries considerably.ESSAYSome usefull metal usually banded on ore mineral together with the others chemical elements. This mineral usually spreaded in rock and soil consists of framer mineral rock that little contains metals. Usually this mineral mineral non metals called as gangue. The alloy of ore mineral and mineral gangue will become ore mineral. Some of ore mineral have shine metal like kalkopirit, cuprit, and also there were have not shine metals like malakhit, bauksit, sfalerit, and usually combine with other element such as Al, Si, S, O . Because of that people can take 1 element from kind mineral the example copper can taken from mineral kalkopirit, malakhit, cuprit and azurit. Ore Mineral can aslo classified be primer mineral ( hipogene ) defined as mineral formed together with others mineral and not yet weathering and secunder mineral ( supergene ) defined as mineral from the results of weathering on rockGangue mineral is part of association mineral that forming rock and doesnt ore mineral on trapped rock. This showed kind of original mineral gangue : KindNameCompositionHipogeneSupergene

OxideOxideSiO2XX

Others silicaSiO2XX

BaucsitAl2O3.2H2O-X

CarbonatKalsitCaCO3XX

DolomitCaMgCO3XX

SideritFeCO3XX

RodokhrositMnCO3X-

SulphatBaritBaSO4X-

GipsCaSO42H2O-X

SilicateFelspar*X-

Garnet*X-

RodonitMnSiO3X-

Chlorit*X-

Mineral Clay*XX

OthersRock*XX

FluoritCaF2X-

ApatitCaF( CaPO4)3X-

PiritFeS2XX

MarkasitFeS2XX

PyrrhortitFe1-xSX-

ArsenophiritFeAsSX-

Note :*Complex Composition or easy to change x availableAs produsen of metals, that mineral is useless but for other necessity will have specific value, the example in mining lead ore in Bangka Belitung that mineral gangue in form kaolin and kuarsa. Ore mineral in that table can be called as the mixture of ore mineral and mineral gangue that can be mined and profit. The example is pirit contains Au cant called as ore mineral because that precentage is slow and the cost is very expensive to release the gold. Although high precentage gold, but cost of mining and separating that gold is not balanced with disposal cost, mineral pirit can not be callled as ore.The Development of technology maybe will change the status from not ore be ore. The example of gangue ore mineral before world war II spodumen is costless but with the improvement of technology of rcoket, spodumen is usefull because that mineral can be used for porcelain resistance with high temperature. The collection of mineral that mined as ore depends on mineral gangue or the others mineral although on a few number, because they have possibility can be used, the example is ore timbel, lead or copper be valueless because contains of bismuth ( Bi), Arsen ( As ), or cadmium. Bi, As, Cd although in a few amount is very hard to separated. Gangue Minerals very usefull to industrial mineral and material processing one the example in Separation of low grade nickel ore. Density separation is widely used to pre-concentrate ore minerals and reject unwanted gangue prior to the main processing stage of an ore (e.g. flotation). For base metal sulfide ores, dense medium separation (DMS) is used to separate the sulfide minerals, which are relatively dense, from the less dense silicate gangue minerals. With pre-concentration it is possible to reject a large portion of the run-of-mine (ROM) mass, with a metal grade that is equal to or less than the tailings grade that would have been achieved by the main processing stage, in this case, flotation (Creswell, 2001).The consequent metal upgrade of the feed can result in the exploitation of deposits previously considered to be uneconomic. The Tati Nickel Mine in Southeast Asia is an example of where Ni ore is successfully pre-concentrated using DMS before being fed into a flotation plant. Other benefits include the energy and cost savings due to the reduction of silicate gangue fed to the milling and flotation plant, as well as the improved feed grades that potentially result in improved metal recovery and concentrate grade. A reduction in the amount of silicate gangue introduced into the circuit will also lower the reagent costs associated with depressant addition (Creswell, 2001).

Results:Dense Medium SeparationA summary of the DMS results is given in Table 1. The mass recovery to the sinks was 48% at a density cut point of 3.0 g/cm3, which is in agreement with preliminary HLS testwork conducted on the feed sample. The Ni was upgraded from 0.39% to 0.67% at a recovery of 83%. No significant Cu upgrade was achieved. Table Summary of DMS testwork at a cut point of 3.0 g/cm

The Ni grades and recoveries, as well as mass distribution of the bulk sample, were calculated. for different streams of the flowsheet, from the ROM material to the calculated flotation feed sample. The data have been mass-balanced with variability in the measured and smoothed grades less than 5%.Overall the Ni showed a 54% upgrade from 0.4% in the ROM to 0.7% in the flotation feed, with an 87% Ni recovery to the flotation plant. Approximately 44% of the ROM mass was rejected in the DMC overflow, with the Ni grade of the overflow at 0.1%.

Flowsheet for the testwork showing different streamsBeside the effect on gangue mineral in separation nickel ore, there were also the effect on gangue minerals in hydrophobic at recovery gold. using ores obtained from the active small scale gold mining sites in southeast asia. Gold ores of different gangue contents were tested. The effects of silica gangue and high sulphide gangue on gold attachment were examined including the effect of surface activators (potassium amyl xanthate) and the possibility of depressing the effects of gangue using reagents. The presence of gangue minerals in gold ores is among the main reasons for the selection of appropriate gold recovery method. The common gangue minerals which are normally associated with gold ores include quartz, fluorite, calcite, pyrites, chalcopyrites, galena and many others in small amounts e.g. arsenopyrites, fluorites, carbonates and chloritesThe hydrophobic recovery of gold is dependent on greater oleophilicity and hydrophobicity of gold com- pared to many other minerals. However it is known that some of the gangue minerals that are associated with gold have oleophilic and hydrophobic properties and the presence of such mineral gangue in the ore may be a source of competition during the attachment to agglom- erates. Such minerals include mainly the metallic sul- phides gangue. The presence of low amounts of sulphides in the ore up to 5% chalcopyrite is reported to have little effect on gold recoveries.This work is focused on the effects of high sulphides and other gangue on gold recoveries using the hydropho- bic recovery of gold. Potassium amyl xanthate was the reagent used as surface activator in the tests. This work was done as a contribution to the ongoing research on the application of the hydrophobic recovery of gold as an alternative to the hazardous use of mercury in small scale gold mining The results were evaluated in terms of gold recovery, volumes and grade of concentrates formed. There was no change in gold recoveries when the amount of oxide gangue (quartz) in the ore was increased, indicating absence of competition between gold and quartz gangue. High sulphide contents in the ore above 6% reduced gold recoveries considerably. It was noted that potassium amyl xanthate surfactants increased the attachment of both gold and the sulphide gangue. Using lime at pH 10 it was possible to depress the sulphide gangue which is mainly pyrite and hence increased gold recoveries considerably

Concentrate weights attained due to gangue recovery (with surfactant).There was no change in gold recoveries when the amount of quartz gangue in the ore was increased, suggesting the existence of quartz particle hydrophilicity due to reaction between the polar surface and the water dipoles.References :B. A. Wills and N. M. Tim, Mineral Processing Technology; An Introduction to the Practical Aspects of Ore Treatment and Mineral Recovery, 7th Edition, Elsevier Science & Technology Books, 2006, p. 269.Cresswell, G.M., 2001 Pre-concentration of base metal ores by dense medium separation. SAIMM Copper, Cobalt, Nickel and Zinc Recovery Conference, 10 pp.J. P. Calvez, M. J. Kim, P. L. Wong and T. Tran, Use of Coal-Oil Agglomerates For Particulate Gold Recovery, Minerals Engineering, Vol. 11, No. 9, 1998, pp. 803-812.Sukandarrumidi, 2007, Geologi Mineral Logam explorer muda, Gadjah Mada University Press, Yogyakarta, p. 3-20.

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