The thiourea gold extraction process is a new technology in the world of gold smelting. The thiourea gold extraction workshop of Longshui Concentrator is the first relatively complete industrial experimental plant in China. The thiourea gold extraction process is a new technology in the world of gold smelting. The thiourea gold extraction workshop of Longshui Concentrator is the first relatively complete industrial experimental plant in China. The thiourea gold extraction is non-toxic, and the cost is similar to the conventional cyanidation method. It is more advantageous for the gold extraction of gold-sulfur- arsenic minerals in China. Table I Steel Ball Hinge,Heavy Duty Hinge,Steel Long Hinge,Hinge Long Continous Guangdong Haitan electric cabinet lock Co., Ltd , https://www.htcabinetlock.com
(1) Ore properties: The Longshuiling ore is a medium-temperature fissure-filled gold-bearing sulphide deposit, and the ore body is in contact with the Huanggangyan and sand shale formations. Metal ore minerals are mainly pyrite, followed by well-lead ore, copper ore yellow, small amounts of sphalerite, bornite, and natural gold. Gangue minerals quartz, a small amount sericite, dolomite, calcite, barite and the like.
Natural gold is mainly distributed in the pyrite fissures, and is generally symbiotic with pyrite and quartz. The size of the gold inlay is not uniform, and the particle size is fine, and most of them are below 0.1 mm, generally 0.01 to 0.006 mm. The ore density is 2.87t/m 3 and the Platts hardness is 8~10.
(2) Process: The gold-containing sulfur concentrate is obtained by flotation. After the concentrate is re-ground, the thiourea leaching and iron plate replacement are performed, and the gold mud and by-product sulfur concentrate are produced. After the gold mud is smelted, the final product is combined. The process flow is shown in the figure below. 
The process has passed the semi-industrial test of the Yu'erya Gold Mine and the Zhangjiakou Gold Mine in Hebei Province, and the industrial test of the Longshui Gold Mine shows that the leaching replacement process index is higher, and the thiourea leaching and iron replacement are completed in the same process, and the process is shorter. The workshop design has automatic devices for the extraction, cleaning and gold mud peeling of the replacement iron plates, and has achieved good results. The disadvantage is that the iron plate replacement is prone to pits on the plate and shortens the service life of the iron plate, and the iron content in the gold mud is high, which increases the complexity of the gold smelting. To this end, from the future process development and perfect production, the thiourea-carbon slurry method (resin slurry method) gold extraction should be studied to improve the thiourea process gold extraction and smelting process. The process indicators of Longshuiling Concentrator are shown in Table 1. The unit consumption indicators are shown in Table 2. The main equipment is shown in Table 3.
Table II
Table 3
Longshui Gold Mine Longshuiling Concentrator
Long Ridge mineral water plant design capacity of 100t / d, 1979 put into operation. In 1984, another 10t/d thiourea gold extraction workshop was built.