After entering the ore dressing plant after crushing, grinding and flotation, separation of useful minerals in the ore is one or more concentrate products. In a state of discharge of tailings slurry. The concentrate yield is small, the concentrate yield of nonferrous metal concentrator is only 10%-20%, the quantity of tailings is very large, and the yield is generally 80%-90%. If a day is a small dressing plant of 100 tons, daily emissions of tailings up to 80-90 tons; ore grade is high, the rate of concentrate, tailings is less.

On the other hand, the concept of tailings is relative, tailings contain a large number of useful ingredients. The original technical water problems, some precious metals, rare metals can not be recycled, but with the progress of science and technology, the useful components of the tailings can be re developed. The comprehensive utilization of tailings resources at home and abroad, there are many examples, such as Hubei Province copper records containing gold and silver, copper, iron and other useful components rich mine tailings, in recent years with the development of processing technology, 1985 of the mine tailings by weak magnetic - high intensity magnetic separation technology, every year tens of thousands of tons of iron recovery concentrate from tailings, worth millions, are further tailings regrinding, gold and silver, copper, iron and other useful minerals in tailings can be fully recycled, thus greatly improve the economic benefit of the mine.

China's tailings utilization rate is only about 7%, mostly in the form of tailings stockpiling. Tailings stockpiling a series of harm to the environment, such as the occupation of cultivated land and waste of mineral resources, seriously affected the tailings ecological environment, prone to security risks. At the same time, the utilization rate of mineral resources in China is about 30%, an average of less than 20 percentage points lower than foreign countries, on the mining recovery rate, gold up to 67.5%. With the depletion of resources and the improvement of environmental protection requirements, more and more attention has been paid to the comprehensive utilization of gold tailings.

According to the nature of the differences and the gold tailings recycling group, the general idea for the recovery of the main products of gold and silver from tailings in the way of our country at present, the early gold grade is high, and the past gold of backward technology, equipment efficiency is not high, three of associated elements of recycling level is not high, so many years of gold the gold tailings grade of about 1.0g/t, some as high as 2 ~ 3.0g/t. The comprehensive utilization of the old and new gold mine tailings, the recovery of gold and silver in the present stage of the feasibility of the larger. Recovery of other metals from gold tailings. A lot of gold ore in China associated with copper, lead, zinc, iron, molybdenum, bismuth, sulfur and other elements, according to the survey found that some old mine tailings of lead and sulfur grade more than 1% more than 8%, more than 0.2% copper and zinc is greater than 0.5%, which has a certain value in the recovery of technical and economic conditions at the present stage. Construction materials of gold tailings. Type of gold deposits in China is complex, many kinds of rock, part of the content of metal sulfide deposits are scarce, gangue minerals is relatively pure, the tailings do non-metallic materials or building materials. For example, low sulfur gold deposit type volcano tuff, elements of the tailings is rich in silicon, aluminum, can be directly pressed into bricks or used as cement raw materials. Quartz vein type gold deposit has high quartz content, low content of iron, titanium and sulfur, and can be used as casting sand, glass raw material or metallurgical solvent.

The gold tailings beneficiation process, the first of the original tailings by hydrocyclone group will other useless elements single gangue and lean ore intergrowths useless and the proportion of relatively light as much as possible run tail, and then by spiral chute roughing, in group were chosen for the gravity separation, spiral chute to concentrate to the dressing table selection is further purified by purifying the obtained gold concentrate, middling spiral chute is neither at monomer dissociation will grind to 0.074mm (200 to 85% by using cyclone group control grade) then mortar pump supplying centrifugal concentrator to get the final gold concentrate. If the gold tailings also contains other valuable and rare elements and the specific gravity and gravity can be used to solve the approximation, the maximum possible flotation process can not be recovered fully, the tailings of valuable elements in the comprehensive recovery, is an important measure to improve the utilization rate of resources, not only improves the recovery rate of resources, but also to the enterprise has brought enormous economic benefits.

With the rapid development of iron and steel industry, the proportion of iron ore tailings in industrial solid waste is increasing. According to incomplete statistics, at present in our country there are more than 150 kinds of mineral development, established more than 8 thousand mines, the cumulative production of 5 billion 970 million T tailings, the amount of iron tailings stockpiling accounted for nearly 1/3 of the total of all tailings.

Classification of iron tailings: Iron Tailings in China can be divided into two categories: single metal iron tailings and multi metal iron tailings. The single metal iron tailings, according to the content of silicon, aluminum, calcium and magnesium can be divided into the following categories: (1) high silicon iron tailings in Anshan. This type of tailings is the largest number of iron tailings, tailings containing high silicon, some containing Si02 up to 83%. This kind of tailings generally does not contain the price associated elements, the average particle size of 0.04mm. 0.2mm. This is belongs to the mineral processing plant of Benxi Iron and steel Nanfen, Waitoushan, East Anshan, Qi Dashan, Gongchangling, Anshan, Shougang, Dagushan, Miyun, Dashi river water, TISCO Ekou, Tangsteel Shirengou etc.. (2) high aluminum Maanshan Iron tailings. The tailings discharged years the amount is not large, is mainly distributed in the middle and lower reaches of Yangtze River in Nanjing Wuhu area. Such as Jiangsu Jishan iron ore, Masteel Gushan Iron Mine, iron ore and iron ore in Huangmei Nanshan Mountain mineral processing plant. Its main characteristic is that the content of A1203 is high, most of the tailings do not contain the associated elements and components, and the individual tailings contain associated sulfur and phosphorus, which is less than 0.074mm particle size of 30% ~. (3) high calcium and magnesium iron tailings in Handan. The tailings mainly concentrated in the Handan area, such as the Yushiwa iron mine, West Shimen, Jade Spring Ling, Fu Shan, Wang Jia Zi etc.. The main associated elements are S, Co, very small amounts of Cu, Ni, Zn, Pb, As, Au and Ag and so on, which are less than 0.074mm of 50% ~. (4) low calcium, magnesium, aluminum, silicon Jiuquan Iron tailings. The main non metallic minerals in the tailings is barite, Jasper, Co, Ni and associated elements are Ge, Ga and Cu, tailings particle size less than 0.074mm accounted for 73.2%. The multi metal tailings are mainly distributed in the southwest of Panxi area, Inner Mongolia Baotou area and the middle and lower reaches of the Yangtze river. This kind of iron tailings is characterized by complex mineral composition, associated elements, in addition to rich in non-ferrous metals, but also contains a certain amount of rare metals, precious metals and rare elements. From the value point of view, the recovery of iron ore tailings associated elements, has far exceeded the recovery value of the main metal iron. Such as the Daye iron tailings contains high iron, containing Cu, Co, S, Ni, Au, Ag, Se etc; Panzhihua Iron Tailings contains a considerable amount of V, Ti, Co, Ni, also contains Ga, S and so on; iron minerals, 8.6% Baiyunebo iron tailings containing 22.9% the rare earth mineral and 15.O% fluorite etc..

Properties of iron ore tailings: iron tailings is concentrator in specific economic and technological conditions, the ore grinding, select the "emissions of useful components after the waste is the solid waste residual ore concentrate after selected. It is a kind of composite mineral raw materials, in addition to containing a small amount of metal components, the main mineral component is the gangue minerals, such as quartz, feldspar, pyroxene, garnet, amphibole and altered minerals: the main chemical constituents of iron, silicon, magnesium, calcium, aluminum oxide, and accompanied by a small amount of phosphorus. Sulfur. Is an important two resource.

Tailings beneficiation technology, tailings beneficiation process flow, tailings beneficiation method: (gold ore tailings as an example)