1. Prevent air pollution When the sulfide ore is purified, it generates acid. When the acid reacts with sodium cyanide, it will produce highly volatile and highly toxic substance, hydrogen cyanide (HCN), which will pollute the air. In order to prevent the formation of hydrocyanic acid gas, it is necessary to add a base such as lime or sodium hydroxide to the solution to control the pH to above 10. To obtain perfect joins, inside of the solder ring copper fitting and the outside of the copper pipe are cleaned using coarse steel wool, flux paste is applied, the pipe is then inserted into the fitting and heat applied from a portable propane torch until a ring of solder shows at the edges of the fitting. Sizes we have available are from 8mm to 54mm For EN1254-1 and 1/2" to 2" for ASME B16.22 ,solder ring Copper Fittings,presolder copper fittings,yorkshire copper fittings,pegler copper fittings,connex copper fittings solder ring copper fittings,presolder copper fittings,yorkshire copper fittings,pegler copper fittings,connex copper fittings Taizhou Runde Company , https://www.zjbronzefittings.com
2. Prevent groundwater pollution 1) The heap leaching field must prevent the venom from leaking underground. The pile leaching field is required to be concrete masonry, and the surface is coated with high-grade cement. After drying, a layer of asphalt is applied , and the plastic film is laid on the asphalt, or in the sand. The soil layer is compacted, leveled and then covered with a plastic film. For long-term use of heap leaching sites, wells can be dug under the groundwater flow, intercepting water to change the flow direction, and periodic detection of cyanide content.
2) The facilities used for heap leaching, such as tanks - storage tanks, high tanks, and pipes, must be protected against dripping. The tank body can be made of steel plate or concrete, and the surface is painted with waterproof material such as asphalt paint or epoxy resin. Rubber pipes, plastic pipes or iron pipes can be used for pipes. Be careful of dripping at joints and valves.
3) Heap leaching production is generally carried out in the open air. The maximum rainfall data should be collected and mastered during the engineering design. The design capacity of the precious liquid pool can withstand the maximum rainfall torrent to avoid pollution caused by heavy rain.
3. Wastewater and waste slag discharge measures 1) The wastewater to be discharged must be disinfected and allowed to discharge before reaching the standard;
2) Before the waste residue is discarded, it should be washed several times with alkaline water, then washed with bleaching powder aqueous solution until the cyanide content reaches the discharge standard, transported to a remote area for disposal and stored safely, and naturally purified.
4. Strengthen personal protection, strict operating procedures to ensure personal safety 1) Operators must wear labor protection products as required;
2) The operation requires strict control of the pH of the solution to prevent the formation of hydrocyanic acid;
3) In the operation, it is necessary to strictly control the volume of the spray liquid, the liquid storage and the circulating fluid to maintain the balance, so as to prevent the liquid storage accident of the storage tank from occurring;
4) In cyanide handling, handling and unpacking, the risk of cyanide solids coming into contact with the skin and inhaling cyanide solid dust should be avoided.
Measures taken to prevent pollution in gold production by cyanide heap leaching