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PROCESSING OF THE GOLD ORE FROM KEDONDONG AREA, SOUTH LAMPUNG USING GRAVITY CONCENTRATION METHOD Lili Tahli; Tatang Wahyudi
Indonesian Mining Journal Vol 16, No 1 (2013): INDONESIAN MINING JOURNAL Vol. 16 No. 1 February 2013
Publisher : Puslitbang tekMIRA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2382.511 KB) | DOI: 10.30556/imj.Vol16.No1.2013.439

Abstract

Kedondong gold ores seem promising to be processed. Referring to its mineralogy characters, the ores can be treated by gravity concentration method that include Knelson concentrator, shaking table, jig and sluice box as well. Processing the gold sample coded A from Kedondong, South Lampung by Knelson concentrator increased the Au grade from 21.87 to 399.76 g/t. Its recovery was 91.57 %. The silver grade also improved from 287.83 to 3,427.12 g/t performing recovery of 49.65 %. Re-processing Knelson concentrator concentrates using shaking table enlarged the Au and silver grades to 1,199.28 and 5,430.80 g/t respectively. Both Au and Ag recoveries were around 89.84% and 47.45% respectively. Another sample, coded B, provided grade 165.80 g/t Au (from 8.93 g/t) and 3,275.05 g/t Ag (from 172.73 g/t) when processed by Knelson concentrator. A shaking table process for such a B-Knelson concentrate yielded the Au and Ag grades to 710,05 and 13.800,80 g/t respectively and also improved the Au and Ag recoveries to 85.56 and 85.17%. Concentrate Sample A has satisfied the requirement for final processing using smelting method, however, Sample B still needs more shaking table process in order to get satisfied condition for smelting process, namely the grade of gold >1,000 g/t.
IMPACTS OF ARTISANAL GOLD MINING AND EFFORTS TO MINIMIZE NEGATIVE IMPACTS TO THE ENVIRONMENT HUSAINI HUSAINI; LILI TAHLI; MUTA’ALIM MUTA’ALIM
Indonesian Mining Journal Vol 15, No 3 (2012): INDONESIAN MINING JOURNAL Vol. 15 No. 3 October 2012
Publisher : Puslitbang tekMIRA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (354.677 KB) | DOI: 10.30556/imj.Vol15.No3.2012.451

Abstract

Indonesia has extensive primary and secondary gold ore deposits that are scattered at several islands. The processing method for gold includes cyanidation, amalgamation and gravity concentration. Amalgamation is one of the most dangerous methods that pollutes the environment. The process is conducted by artisanal gold mining extensively throughout the country and involving around 100.000 miners. The process is started by crushing the ore up to 2-3 cm, then put in the trommel along with Hg and water. The trommel is then rotated for 4-5 hours to produce amalgam (Au-Hg) to be separated from its tailing by panning. The clean Au-Hg, mixed with liquid Hg, is then squeezed to separate the Hg excess. The Au-Hg, mixed with borax is then burnt in a crucible to evaporate its Hg and get the golds bullion (Au-Ag metal). The gold is obtained after the silver within the bullion is leached by HNO3 equipment used for burning the Au-Hg is an open vessel that is operated in the kitchen at which the people also cook the food. This condition is very dangerous for the miner and their families as the Hg vapor is very toxic and can damage human lung. Another problem is that Hg-containing fine tailings are directly discharged to the river. This mercury can pollute the aquatic system and become dangerous for human through food chain. The efforts decreasing the negative effect of artisanal mining employ a retort to burn the amalgam, centralize the trommels; concentrate the gold ores prior to amalgamation. Jig, shaking table, sluice box can be used for upgrading the gold. If tailing with relatively high gold content would be processed by gravity concentration or cyanidation, the location for tailing gold processing should be safe and far from the river and houses.
PROCESSING OF THE GOLD ORE FROM KEDONDONG AREA, SOUTH LAMPUNG USING GRAVITY CONCENTRATION METHOD Lili Tahli; Tatang Wahyudi
Indonesian Mining Journal Vol 16 No 1 (2013): INDONESIAN MINING JOURNAL Vol. 16 No. 1 February 2013
Publisher : Balai Besar Pengujian Mineral dan Batubara tekMIRA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30556/imj.Vol16.No1.2013.439

Abstract

Kedondong gold ores seem promising to be processed. Referring to its mineralogy characters, the ores can be treated by gravity concentration method that include Knelson concentrator, shaking table, jig and sluice box as well. Processing the gold sample coded A from Kedondong, South Lampung by Knelson concentrator increased the Au grade from 21.87 to 399.76 g/t. Its recovery was 91.57 %. The silver grade also improved from 287.83 to 3,427.12 g/t performing recovery of 49.65 %. Re-processing Knelson concentrator concentrates using shaking table enlarged the Au and silver grades to 1,199.28 and 5,430.80 g/t respectively. Both Au and Ag recoveries were around 89.84% and 47.45% respectively. Another sample, coded B, provided grade 165.80 g/t Au (from 8.93 g/t) and 3,275.05 g/t Ag (from 172.73 g/t) when processed by Knelson concentrator. A shaking table process for such a B-Knelson concentrate yielded the Au and Ag grades to 710,05 and 13.800,80 g/t respectively and also improved the Au and Ag recoveries to 85.56 and 85.17%. Concentrate Sample A has satisfied the requirement for final processing using smelting method, however, Sample B still needs more shaking table process in order to get satisfied condition for smelting process, namely the grade of gold >1,000 g/t.
IMPACTS OF ARTISANAL GOLD MINING AND EFFORTS TO MINIMIZE NEGATIVE IMPACTS TO THE ENVIRONMENT HUSAINI HUSAINI; LILI TAHLI; MUTA’ALIM MUTA’ALIM
Indonesian Mining Journal Vol 15 No 3 (2012): INDONESIAN MINING JOURNAL Vol. 15 No. 3 October 2012
Publisher : Balai Besar Pengujian Mineral dan Batubara tekMIRA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30556/imj.Vol15.No3.2012.451

Abstract

Indonesia has extensive primary and secondary gold ore deposits that are scattered at several islands. The processing method for gold includes cyanidation, amalgamation and gravity concentration. Amalgamation is one of the most dangerous methods that pollutes the environment. The process is conducted by artisanal gold mining extensively throughout the country and involving around 100.000 miners. The process is started by crushing the ore up to 2-3 cm, then put in the trommel along with Hg and water. The trommel is then rotated for 4-5 hours to produce amalgam (Au-Hg) to be separated from its tailing by panning. The clean Au-Hg, mixed with liquid Hg, is then squeezed to separate the Hg excess. The Au-Hg, mixed with borax is then burnt in a crucible to evaporate its Hg and get the golds bullion (Au-Ag metal). The gold is obtained after the silver within the bullion is leached by HNO3 equipment used for burning the Au-Hg is an open vessel that is operated in the kitchen at which the people also cook the food. This condition is very dangerous for the miner and their families as the Hg vapor is very toxic and can damage human lung. Another problem is that Hg-containing fine tailings are directly discharged to the river. This mercury can pollute the aquatic system and become dangerous for human through food chain. The efforts decreasing the negative effect of artisanal mining employ a retort to burn the amalgam, centralize the trommels; concentrate the gold ores prior to amalgamation. Jig, shaking table, sluice box can be used for upgrading the gold. If tailing with relatively high gold content would be processed by gravity concentration or cyanidation, the location for tailing gold processing should be safe and far from the river and houses.