APPLICATION OF INNOVATIVE PROCESSES FOR GOLD RECOVERY FROM ROMANIAN MINING WASTES (original) (raw)

Valorization of Mining Waste by Application of Innovative Thiosulphate Leaching for Gold Recovery

Metals

The metals and industrial minerals contained in the tailings of mining and quarrying activities, can degrade natural environments as well as human health. The objective of this experimental work is the application of innovative and sustainable technologies for the treatment and exploitation of mining tailings from Romania. Within this approach, the recovery of high grade raw materials to be placed on the market is achieved and reduction of these wastes volume are achieved. The current study is focused on hydrometallurgical process for the recovery of gold. The innovative treatment chosen is the thiosulphate process that, compared with the conventional cyanide, has several advantages (e.g., it is more ecologically friendly and is not toxic to humans). The conventional cyanidation process shows operating limits in the case of auriferous refractory minerals, such as Romanian wastes, the object of the study. An important characteristic of thiosulphate leaching process it has the best se...

Hydrometallurgical Recovery of Gold from Mining Wastes

2020

Gold is a highly required material for a wide range of personal and industrial applications. The high demand for gold, together with the shortage of natural resources and high pollution potential of wastes generated during mining and ore processing activities led to search for alternative sources of gold. A possible source is represented by mine wastes resulting from the processing of polymetallic or sulfidic ores. The reprocessing of wastes and old tailings with moderate to low content of gold offers not only a business opportunity, but also enhances the quality of the surrounding environment, changes the land use and offers a wide range of socio-economic benefits. Cyanidation, the most widespread Au leaching option, is progressively abandoned due to the high risk associated with its use and to the low public acceptance. Therefore, alternative methods such as thiocyanate, thiourea, thiosulphate and halide leaching gained more and more interest. This chapter presents the most import...

Valorisation of Mining Waste for Gold Recovery

2018

Purpose: the metals and industrial minerals contained in the tailings produced by mining and quarrying activities, are cause of environmental damage. The objective of this experimental work is the application of innovative technologies for the treatment and exploitation of mining tailings in Romania, in order to recover materials high grade raw to be placed on the market, reducing the volume of the wastes. Further objective, is to optimize some parameters relating to the dissolution of gold and the subsequent recovery from purified solutions, determining beforehand the technical feasibility of the scheme of process developed on a laboratory scale. Methods: the study is focused on hydrometallurgical process for the recovery of gold. The innovative treatment chosen is the thiosulphate process that, compared to conventional cyanide, has several advantages, first of all the most eco-friendly and nontoxic to humans. The conventional process shows operating limits in the case of auriferou...

Electrolysis of Gold from Filtration Waste by Means of Mechanical Activation

2012

The intensification of the gold thiourea leaching from a filtration waste (Kosice, Slovakia) using mechanical activation as the pretreatment step has been studied. The leaching of “as-received“ sample in an acid thiourea solution resulted in 65 % Au dissolution. However, after mechanical activation in a planetary mill 99 % of the gold was leached. The optimum redox potential for electrolysis is in the range 500-523 mV for the gold extraction 99.79 % from the mechanically activated sample. The mechanical activation resulted in an increase of the specific surface area of the waste from 0.7 m 2 g -1 to a maximum value of 13.5 m 2 g -1 . The physicochemical changes in the filtration waste as a consequence of mechanical activation had a pronounced influence on the subsequent gold extraction.

Leaching of gold from a mechanically and mechanochemically activated waste

Acta Montanistica Slovaca, 2010

The intensification of leaching of gold from a waste using mechanical activation (milling in water) and mechanochemical activation (milling in thiourea solution) were studied as the pretreatment steps. The leaching of “as-received“ sample in an acid thiourea solution resulted in 78 % Au dissolution, after mechanical activation 98 % and mechanochemical activation up to 99 % of the gold was leached during 120 min. The mechanochemical activation resulted in an increase of the specific surface area of the waste from 0.6 mg to a maximum value of 20.5 mg. The activation was performed in an attritor using variable milling times. The physico-chemical changes in the waste as a consequence of mechanochemical activation had a pronounced influence on the subsequent gold extraction.