Bibliographic citations
Chaucayanqui, B., (2012). Modelo de planta piloto para recuperación del Oro de la pequeña minería y minimizar los impactos ambientales [Tesis, Universidad Nacional de Ingeniería]. http://hdl.handle.net/20.500.14076/1081
Chaucayanqui, B., Modelo de planta piloto para recuperación del Oro de la pequeña minería y minimizar los impactos ambientales [Tesis]. : Universidad Nacional de Ingeniería; 2012. http://hdl.handle.net/20.500.14076/1081
@mastersthesis{renati/255271,
title = "Modelo de planta piloto para recuperación del Oro de la pequeña minería y minimizar los impactos ambientales",
author = "Chaucayanqui Quisa, Bruno Emilio",
publisher = "Universidad Nacional de Ingeniería",
year = "2012"
}
Due to the environmental problems caused by practices such as mercury amalgamation, characteristics of small gold mining, artisanal or informal localized in Secocha, Misky and Yanaquihua, affecting Ocoña River Basin Arequipa, the commitment of professionals involved in the sector is and will be a constant search for alternative technologies or cleaner for gold recovery; as the centrifugal gravity concentration, dense media, magnetic or flotation, obviously cleaner and for this reason, it is proposed a model pilot plant of 25 TMD installed capacity for gold recovery for small-scale mining and to minimize environmental impacts. The mineral was characterized via electron microscopy that determined there are three types of gold present in the ore-free study: (a) nanometric, called ultrafine (2) micrometric with sizes smaller than 5 microns, fine and (c) micrometric with particle size between 20 and 50 microns, "coarse aggregate" and a type gold called electrum, therefore scheduled metallurgical processes were oriented towards gravity concentration via Falcón or Jig. For this purpose, the experimental procedure consisted on sampling and preparing 35 kg of gold ore (head grade 77,87 g Au/TM) for microscopy electron studies, determination of physical characteristics, chemical analysis and metallurgical testing (gravity concentration Falcon, Jig, cyanidation and flotation), as well as moliendability tests were performed to calculate the work index. Gravity concentration tests were performed via Falcón and Jig, both with 5 kg of fresh ore to a granulometry of 80%-100m as feeding, forming a pulp of 25% solids. In the first case, chemical analysis using assay fire method for gold by gravity, a grade observed in the concentrate of 830,7 g Au/TM that represented a recovery of 57,97% and the atomic absorption method for the analysis of silver, provides evidence of a concentrated grade of 469 g Ag/TM and 21,76% of recovery. Meanwhile, the cyanidation in bottles took place using 1 kg of fresh mineral-at 80%-200m for 48 hours, getting the rich solution (alkaline) and solid waste or cuttings, which was subsequently analyzed, resulting in 35,48 g Au/TM and 26,96 g Ag/TM, making a recovery of 91,14% for gold and 54,46% for silver. Analogously, using 1 Kg of the Falcón gravimetric tailings at 80% -200m, during 48 hours obtaining a rich solution (alkaline) and solid waste or cuttings which were also analyzed, resulting in 15,4 g Au/TM and 30,9 g Ag/TM, reaching recoveries of 87,4% and 62,73% respectively. The resulting free cyanide of both tailings cyanidation amounted to 10-4 mg/L, a value that is very low compared with current environmental regulations (1 mg/L), making it environmentally viable the alternative Flowsheet A (flowsheet Nº 1). It was finalized with flotation tests “rougher”, also using fresh ore and tailings from concentrator Falcon, at 80%-200m, for 15 minutes with 50% solids in ball mill. For the first case fresh ore, the ore-grades obtained in the concentrated were 534.8 g Au/TM and 723,9 g Ag/TM, which accounted for 96,88% recovery for gold and 89,74% for silver. In the case of flotation using tailings from concentrator Falcón, ore-grades were obtained in the concentrated were 221,00 g Au/TM and 545,40 g Ag/TM, representing recovery of 94,16% and 84,33% respectively. This sequence of procedures is described in the alternative flowsheet B (flowsheet Nº 2). With regard to economical and financial study, it is required an investment of US $ 215 000, for the implementation of the pilot plant of 25 TMD model (in equipment procurement, construction and development of DIA), with real annual incomes of US $ 1 819 482, treatment costs of US $ 1 600 000 and depreciation of US $ 30 000 annually, with economical indicators: VANE US $ 293 594,96, TIRE 70,38% and profit / cost of 2,37 and PAY BACK of 2 years. The result was to apply the gravity concentration Falcón in combination with cyanidation, a cleaner method. It is concluded that the planning for the minimization of environmental impacts, previously identified from the factors potentially affected (physical, biological and socioeconomical-cultural), can be considered moderately significant. The flotation tailings and cyanidation cuttings, that were produced by paths sheet flow Nº 1 and Nº 2 respectively, doesn’t offer risk of contaminating either soil or bodies of water due to they will be available in a previously waterproofed with protectives geomembranes. if it were the case that it would exceed of time of operation of 5 years then these residues after pretreatment detoxification undergoing natural degradation of cyanide or oxidizing free cyanide, and dissociated cyanide in weak acids-DAD, by chemical oxidation via hydrogen peroxide. Another alternative would be to determine these residues to produce civil construction materials (such as, bricks and subgrade line), as long as it is subjected to chemical stabilization studies of copper, due to its high copper content (0,335% Cu in cyanidation cuttings from gravity concentration tailings Falcón). Finally this project is viable from the optical technically, economically, environmentally and socially. Keywords: Microscopic characterization; Recovery of gold; Clean technology; Minimization of environmental impacts.
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