leaching of gold from crushed computer waste with thiourea

Mechanism and Clean Procedure to Extract Gold from Printed …

Leaching of gold from the waste printed circuit board During the gold leaching process, the PCB materials were placed in a container, and then a certain concentration of thiourea solution was added into the container, then the system was heated to the experimental temperatures then

Determination of the Leaching Parameters for a Refractory …

Special collections The Albrecht Haupt Collection The Dieter Hennebo Collection Riedel-de Haën Collection European Documentation Centre Trade Union Archives

2HNO 3 6HCl 2NO 4H2 O 3Cl 2 2Au 11HCl 3HNO 3 …

2HNO 3 6HCl 2NO 4H2 O 3Cl 2 2Au 11HCl 3HNO 3 2HAuCl 4 3NOCl 6H2 O 423 Thiourea from CHEM 497 at King Saud University This preview shows page 9 - 12 out of 26 pages.preview shows page 9 - …

CN104894383A

The invention discloses a leaching method of gold and copper in a gold-contained electronic waste. The gold-contained electronic waste is crushed, and the particle size of crushed particles is not more than 2 mm; then, the ball-milling treatment is performed, and the ...

Recycle Technology for Recovering Resources and …

 · Thiourea leaching gold and silver from the printed circuit boards of waste mobile phones. Waste Management 2012, 32 (6), 1209-1212. DOI: 10.1016/j.wasman.2012.01.026. Kanjana Khunathai, Katsutoshi Inoue, Keisuke

Gold Metallurgy and Leaching Process

 · Gold and Silver Leaching. For Gold and Silver, the most common leachants used are Na or K cyanides in the presence of oxygen, Thiourea (NH 2. CS.NH 2 ), also in the presence of oxygen, or Ammonium polysulphide (NH 4) 2 Sx, especially for Gold. Optimum physical conditions for cyanidation …

leaching gold from circuit board powder

 · Sciencemadness Discussion Board – gold from E-waste – … maybe this in not new for those who is in the line of electronic circuit board manufacture. the e-board … is cyanide leaching. … gold with zink powder. »More detailed Ways of Extracting ...

Thiourea Gold Leaching

 · Thiourea Consumption during Gold Leaching. The use of thiourea, (CS (NH2)2 as a complexing/extracting agent for gold and other precious metals has shown promise for implementation in the mining/metals industry. Laboratory testing of this reagent has indicated that a thiourea process for gold extraction has several advantages over conventional ...

Effect of Acid Leaching Pre-Treatment on Gold Extraction from …

 · of thiourea that was expected to form the complex gold-thiourea that is the necessary step to achieve the dissolution of the precious metal [10,19]. Birloaga et al. [20] reports the leaching of spent computer-printed circuit boards, which are different from the

Thiosulfate leaching of gold from waste mobile phones …

 · Gold extraction was found to be enhanced with solutions containing 15–20 mM cupric, 0.1–0.14 M thiosulfate, and 0.2–0.3 M ammonia. Similar trends were obtained for the leaching of gold from two different types of scraps and PCBs of waste mobile phones. From the scrap samples, 98% of the gold was leached out using a solution containing 20 ...

Recovery of precious metals from electronic waste and …

 · Li et al. (2012a) conducted thiourea leaching of gold and silver from the PCBs collected from waste mobile phones. 89.67% of Au and 48.3% of Ag were recovered in the conditions: 24 g/L CS(NH 2) 2, 0.6% Fe 3+ concentration at 25 C for 2 h.

gold leaching with thiourea

 · Thiourea leaching gold and silver from the printed circuit Jun 01, 2012· Highlights Thiourea is a selective and less hazardous agent as an alternative to the conventional and toxic cyanide. The agent was applied to leach gold and silver from PCBs of waste mobile ...

Optimizing and evaluating the operational factors affecting …

 · This research was carried out on Aghdareh gold ore. The Aghdareh mine and gold processing plant is located 32 km from Takab city in the western Azerbaijan province, Iran, at 46 58′30′′N and 36 39′29′′E. The grade of gold ore is 3 ppm. Also, cyanide leaching is].

RECOVERY OF GOLD FROM ELECTRONIC WASTE THROUGH NON …

Effects on gold leaching process 102 4.2.2.(b) Effects on copper leaching process 103 4.2.3 2-stages of copper removal pre-treatment process 105 4.2.4 Effect of oxidants on gold leaching using pre-treated RAMs sample 107

LEACHING OF GOLD FROM FINE-GRAINED FLOTATION TAILINGS

Typically, gold is leached from raw ore [2, 6] or from electrical waste [1]. This research is unique in the sense of the used sample to extract gold using leaching, i.e. gold mining flotation tailings (from waste flotation) have been recovered to leach the residual gold

An advanced study on the hydrometallurgical processing …

 · This study refers to two chemical leaching systems for the base and precious metals extraction from waste printed circuit boards (WPCBs); sulfuric acid with hydrogen peroxide have been used for the first group of metals, meantime thiourea with the ferric ion in

The Extraction of Gold from E-waste by …

E-waste like WPCBs, as the major part of waste, is a considerable source of valuable base metals such as gold, silver, and copper. In recent years, a large number of base and valuable metal recycling activities from PCBs waste have focused on pyrometallurgy process, Kamberovic, et al. Electronic and electrical waste is usually processed using modern methods like pyrometallurgy and ...

How to Use Bleach on Gold Ore to Remove Gold | Sciencing

 · This was the first commercial method used for gold extraction. Place the ore into the mortar and grind it to the size of sand grains. Put the ore grains into a plastic bowl. Add the 35-percent hydrochloric acid to the sodium hypochlorite bleach into a flask or beaker, in a two-to-one ratio of acid to bleach. Ensure that the liquid mixture is at ...

Development of a new method for gold recovery from waste …

4.3.1 Leaching of gold from PCBs of waste mobile phones in ammonium thiosulfate solution-----28 4.3.2 Gold cementation experiments using copper and aluminum powders -----31 4.3.2.1 Effects of copper on gold ion cementation -----31 ...

(PDF) Leaching of Gold and Silver from Crushed Au-Ag …

The thiourea leaching of gold and silver from electronic waste, goldsmith''s waste and ceramic waste using crushing as the pretreatment step was investigated. For electronic waste, it was possible to achieve 97 % gold and 94 % silver recovery within 120 minutes of thiourea leaching.

(PDF) Review of Bioleaching Gold Ores from E-Waste: …

Bioleaching of Gold Ores from E-waste In vat leaching, more finely crushed ore (1- It becomes evident that direct growth of microbes 10 mm) is placed in a large basin (vat) in the The solution is drained off microbial growth and use of microbial metabolites after treatment for metal recovery.

Synopsis for Recovery of precious metals from …

 · Experiment of leaching of gold from waste PCBs with thiourea by Zhang [3] gives better result than previous and the conditions are as follows; solid-liquid 1:5, leaching temperature 350 C, thiourea concentration 10 g/L, Fe3+ concentration 0.3%, H2SO4

Recovery of basic valuable metals and alloys from E-waste using microwave heating followed by leaching …

acid leaching. The e-waste was first crushed and then the sample was melted in microwave heat treatment to ... cyanide, halide leaching, thiourea-based gold leaching, thiosulfate leachant, etc. on hydrometallurgical routes to recover the precious metals from e ...

(PDF) Leaching of Gold and Silver from Crushed Au-Ag Wastes | …

Thiourea bioleaching for gold recycling from e-waste ...

Recycling of gold from waste electronic components of devices

1. Leaching of Gold from Small Components of Electronic Waste Leaching experiments were carried out to study the behavior of gold dissolution using various leachants: cyanide, thiosulfate and thiourea [25-27]. The overall reaction for gold dissolution using each

CN105018725A

The invention discloses a gold leaching solution and a method for recycling gold. The gold leaching solution comprises I2, I-, an oxidation adjuvant and a complexing agent, wherein n ...

Materials | Free Full-Text | Effect of Acid Leaching Pre …

The effect of a preliminary acid leaching for the recovery of gold by thiourea from printed circuit boards (PCBs) of spent mobile phones, was investigated. Preliminary leaching is aimed to recover copper in the leachate that would compete with gold in the successive leaching of the residue with thiourea, thus preventing the formation of the gold-thiourea complex. Two hydrometallurgical routes ...

Thiourea bioleaching for gold recycling from e-waste

 · Thiourea leaching of gold (Au) from e-wastes can be considered an alternative to highly toxic cyanidation, provided that its reagents consumption can be largely reduced. While awareness of the use of biohydrometallurgical techniques in metal mining industries is increasing, the knowledge on microbiological precious metal solubilization is still limited.

Gold Recovery from Electronic Waste by Pressure Oxidation

gold from e-waste focus on the total leaching of metallic fraction [2]. In this regard, leaching studies focus on the use of strong acids (HCl, HNO 3, H 2 SO 4) and oxidative reagents (Cyanide, thiourea, halide, nitrate, iodide, and thiosulfates) [3]–[5].

process extraction of gold

One the ore of gold is found and treated it is crushed to heap leaching and then is sent off for grinding, concentration, and roasting and pressure oxidation. Inquire Now Gold mining Wikipedia Gold mining is the resource extraction of gold by mining. As of 2016

Review of the None-cyanide Leaching Gold from E-waste-

【】:Cyanide leaching of gold had been utilized commercially inmining industry.Yet,cyanide was a high-toxicity chemical associated with serious pollution problems.Nowadays,e-waste recycling technology is not only simply the pursuit of economic efficiency,but more seeking environmental-friendly features.Therefore,non-cyanide hydrometallurgical processing technology for gold recovery ...

Minerals | Free Full-Text | Preliminary Study on Gold …

The present paper is focused on the extraction of gold from high-grade e-waste, i.e., spent electronic connectors and plates, by leaching and electrowinning. These connectors are usually made up of an alloy covered by a layer of gold; sometimes, in some of them, a plastic part is also present. The applied leaching system consisted of an acid solution of diluted sulfuric acid (0.2 mol/L) with ...

Gold extraction

Gold extraction refers to the processes required to extract gold from its ores.This may require a combination of comminution, mineral processing, hydrometallurgical, and pyrometallurgical processes to be performed on the ore. Gold mining from alluvium ores was once achieved by techniques associated with placer mining such as simple gold panning and sluicing, resulting in direct recovery of ...

Technology of Gold Extraction from Mature Dumps by …

 · Despite the above disadvantages, the use of thiourea leaching for extracting gold from technogenic dumps, which does not require additional costs for the processes of ore preparation, has potential. In addition, the suggestion for finding alternative reagents in Tajikistan is attributed to the restricted export of cyanide for the needs of the country.

Leaching of Gold and Silver from Crushed Au-Ag Wastes

The thiourea leaching of gold and silver from electronic waste, goldsmith''s waste and ceramic waste using crushing as the pretreatment step was investigated. For electronic waste, it was possible to achieve 97 % gold and 94 % silver recovery within 120 minutes of thiourea leaching.

Li, J.-Y., Li, X.X. and Liu, W.-Q. (2012) Thiourea Leaching …

Li, J.-Y., Li, X.X. and Liu, W.-Q. (2012) Thiourea Leaching Gold and Silver from the Printed Circuit Boards of Waste Mobile Phones. Waste Management, 32, 1209-1212. Scientific Research An Academic Publisher OPEN ACCESS Home Articles Journals >> ...

(PDF) A Review on Studies and Research on Gold Recovery …

Chatterjee and Kumar Leaching of gold from the waste mobile reviewed electronic waste treatment and phone printed circuit boards (PCBs) was recovery. [24] They proposed an outsourcing carried out by Tripathi et.al. [19] They used model where equal participation of the sodium thiosulphate for the recovery.

Thiourea leaching gold and silver from the printed circuit …

 · The leaching rate of gold increased with an increase of thiourea mass concentrations, while lower leaching rate of silver was obtained when thiourea mass concentration was higher than 24 g/L. This is because thiourea is easily oxidized by ferric ion in acidic solution, and formamidine disulfide is produced when the content of thiourea is too high.

Recovery opportunities of valuable and critical elements …

 · in a second leaching step, thiourea extracted 53 ± 15% of the gold contained in the dust in 1 h. The best leaching conditions (0.25 M thiourea, 0.2 …