Nov 01, 2015· Oh et al. (2003) developed a two-step leaching process, where successful leaching of Cu, Fe, Zn, Ni and Al from circuit boards was carried out using H 2 SO 4 and H 2 O 2 in the first step with >95% recovery. In the second step they recovered Au/Ag using thiosulphate leaching.
Feb 01, 2014· Acid leaching of metals from electronic waste was investigated with inorganic and oxidants acid (HCl, H 2 SO 4, HNO 3 /H 2 O 2, HClO 4, and NaClO). Studies show that the biggest copper extraction from PCB was obtained using HNO 3 /HCl (aqua regia). Acid leaching in presence of an oxidant is also widely used to extract copper from PCBs.
leaching circuits may be improved by optimizing the configuration of. autoclaves and the heat removal method. The objective was achieved by. creating an autoclave model that combines mass balances ...
Examples of a proposed stand-alone HPGR prepared Heap Leach flowsheet and a HPGR CIL/P Heap Leach Hybrid circuit are illustrated in Figures 2.4 and 2.5. The hybrid circuit approach, which utilises a HPGR to prepare ball mill feed for the CIL/P circuit and Heap Leach ore on a campaign basis, is advantageous. Economies of scale can be gained by the
metallurgy - metallurgy - Leaching: Oxides are leached with a sulfuric acid or sodium carbonate solvent, while sulfates can be leached with water or sulfuric acid. Ammonium hydroxide is used for native ores, carbonates, and sulfides, and sodium hydroxide is used for oxides. Cyanide solutions are a solvent for the precious metals, while a sodium chloride solution dissolves some chlorides.
Maximize Precious Metals Recovery with CCD Circuits and High-Density Thickeners. Leaching (lixiviation) is commonly used for recovering a wide variety of metals from ores, including precious metals. A lixiviant dissolves the desired metals from the ore; cyanide leaching, for example, is …
Jul 21, 2021· The rise in the electronics industry has impacted the environment through the large volumes of waste that are improperly disposed of and the growing demand for precious and rare metals from natural sources. Leaching of copper, cobalt, gold, and silver from printed circuit boards of waste cellular phone has been carried out using imidazolium cation-based ionic liquids (ILs). For the studied ...
Heap leaching is an industrial mining process used to extract precious metals, copper, uranium, and other compounds from ore using a series of chemical reactions that absorb specific minerals and re-separate them after their division from other earth materials. Similar to in situ mining, heap leach mining differs in that it places ore on a liner, then adds the chemicals via drip systems to the ...
Feb 02, 2016· Agitated Leaching Circuit Operation -Startup -Shutdown Procedure. Ground slurry from the trash screen enters this EXAMPLE Agitated Leach circuit at a rate of 35.5 cubic meters per hour, and 45% solids. The slurry passes through each of the four tanks, and should remain in each tank for a period of approximately 12 hours.
A schematic of a typical heap leaching circuit is shown in Figure 1, with the main components being: • ore materials processing and handling systems which includes crushing, conveying and stacking equipment; • agglomeration of the ore (if needed) to stabilise the finer fractions and initiate the leaching …
The ammonia leaching tests were carried out to recover valuable metals from alloy obtained from smelting reduction process of mobile phone printed circuit boards. Leaching factors such as kinds of salt, ammonia concentration, and the interaction of metals, which are components of PCB, were investigated to improve the leaching efficiency.
Leach Circuit Design Principles | SRK Consulting. Designing a leach circuit should consider both ore-specific factors as well as factors involving the interaction between the ore and process equipment. Achieving the optimum leach performance involves combining operating parameters, such as grind size, residence time, chemical conditions ...
Tank vs. vat leaching Factors. Tank leaching is usually differentiated from vat leaching on the following factors: In tank leaching the material is ground sufficiently fine to form a slurry or pulp, which can flow under gravity or when pumped. In vat leaching typically a coarser material is placed in the vat for leaching, this reduces the cost of size reduction;
In the present study, the leaching of metals from large pieces of computer printed circuit boards (CPCBs) was studied. A combination of citric acid (0.5 M) and 1.76 M hydrogen peroxide (H 2 O 2) was used to leach the metals from CPCB piece.The influence of system variables such as H 2 O 2 concentration, concentration of citric acid, shaking speed, and temperature on the metal leaching …
leaching circuit. A cyanide leaching circuit usually consists of large agitated tanks for mixing mineral slurry with cyanide in order to extract gold. Typically, the slurry consists of 30-40% solids by weight with the solid particles being less than 100 microns (0.1mm) in size. Air or oxygen is often bubbled through the slurry to improve the ...
Acid leaching is commonly performed by agitating an ore-leach mixture for 4 to as long as 48 hours at ambient temperature. Except in special circumstances, sulfuric acid is the leachant used; it is supplied in amounts sufficient to obtain a final leach liquor at about pH 1.5. Sulfuric acid leaching circuits commonly employ either
Leaching assessment on five heavy metals (copper, zinc, lead, nickel and cadmium) and two brominated flame retardants (BFRs), polybrominated diphenyl ethers (PBDEs) and tetrabromobisphenol A (TBBPA), from waste printed circuit boards (WPCBs) were conducted using various leaching methods. The mean le …
circuit, shown in Figure 1. The temperature of the autoclave is maintained by running cooling water through coils in the vessel. The residence time in the autoclave is approximately one hour. Figure 1. Base case circuit for pressure leaching. The plant is required to double its capacity. To maintain the residence time of the leach, an additional
Apr 21, 2016· Leaching Gold Circuits. This flowsheet is the lowest in price, and can be used on what are commonly termed as "free milling" gold ores where a high percentage of the values are free and where these values are unlocked at reasonably coarse grinding. This flowsheet is often used for treating high grade pockets.
Carbon transfer pumps allow easy carbon movement between tanks if a standard CIL leach circuit is implemented. A CIP pump cell circuit is also popular and can be incorporated into the plant design. Civil design, electrical MCC and wiring, thickeners and pumping circuits are also offered as part of the package offered by Manhattan.
Carbon in Leach Circuit Carbon-in-Leach Circuit (CIL) For over a hundred years, miners have used dilute alkaline cyanide solutions (e.g., sodium cyanide [NaCN] around pH 10-11) to leach (dissolve) gold and other precious metals, from their ores. The gold is usually in …
LEACH military-qualified miniature, subminiature and half-crystal can relays for dry-circuit switching range from low level to 75 amps and come in DC and AC versions. LEACH subminiature relays are hermatically sealed against contaminants, polluants, and the temperature extremes of harsh environments. Many components can withstand vibration and ...
Jul 12, 2021· E-waste is an important secondary source of precious metals. Especially discarded printed circuit boards (PCBs) contain high concentrations of precious metals. In recent years, the bacterial leaching was more widely preferred due to its low environmental impact and cost in the recovery of these precious metals. In this study, a PCBs-adapted pure culture of A. ferrooxidans, A. thiooxidans and ...
to the leaching circuit. The remaining solution now contains mainly ammonium sulphate. This is recovered in the ammonium sulphate plant by evaporationof water, and is sold as Sherritt fertilizer. Since its construction in 1954 to treat nickel concentrates from the Lynn Lake mine, the refinery has undergone several expansions and modifications.
Effect of pH with varying leaching time on the Cu(II)recovery of from waste mobile phone printed circuits board. Experimental conditions, Temperature 60 oC, acid concentration 0.5 M. Temperature greatly affects the leaching kinetics of copper removal from PCBs [8].Cu(II) recovery was prominently influenced with temperature and leaching time, as ...
Corpus ID: 32370569. The process design of gold leaching and carbon-in-pulp circuits @article{Stange1999ThePD, title={The process design of gold leaching and carbon-in-pulp circuits}, author={W. Stange}, journal={Journal of The South African Institute of Mining and Metallurgy}, year={1999}, volume={99}, pages={13-25} }
circuit. In a CIL plant, the carbon granules are added directly into the gold leaching tanks, so that leaching of gold (from the ore phase to the leachate), and adsorption of gold (from the leachate to the carbon), occur simultaneously. In a CIP plant, a series of small adsorption tanks is installed after the leach …
The Sepro Leach Reactor (SLR) is an advanced leaching system for leaching precious metal concentrates generated from gravity concentration circuits; this includes gold leaching.Extensive test work of the Sepro Leach Reactor on-site has shown over 99% of the target mineral can be recovered through a simple, fully automated process that is easily incorporated into gold and silver recovery ...