Xinhai Mining Machinery Design Institute has upgraded and transformed more than 80% of the mineral processing equipment to provide good mineral processing equipment worldwide.
Iron tailings: the iron tailings discharge from iron ore plant is in large amount, fine size and different types, and complex property, so Xinhai use the process of magnetic separation, flotation, acid leaching and flocculation to recover iron.
Gold tailings: Xinhai usually use all-slime cyanide process and carbon-in-pulp process to recover the gold from gold tailings. As for the gold tailings cyaniding, xinhai will apply the method of dry-tailing stacking. That is, though the process of classifying and dewatering, at the same recycling the water recourses to remove the cyanide in it. Moreover, xinhai will use magnetic separation and gravity separation to remove the iron.
Lead-zinc tailings: the main component of the lead-zinc tailings are quartz and suicide sericite. Except the method of stockpiling in tailings pool, dry-tailing stacking and mine filling, Xinhai will also apply gravity separation, flotation separation, magnetic separation, gravity – flotation separation, and other process to recycle the valuable elements.
Copper tailings: if the copper with high heavy metals content, the separation will be easier and apply the process of flotation. If there exist magnetite in the copper tailings, it will firstly using acid leaching to precipitate the copper, then use magnetic separation accordingly.
Fluorite ore tailings: xinhai use the process of flotation to reselect the fluorite, roughing and then cleaning. Before roughing, the pulp and the reagent will be fully stirred. After that repeated cleaning will be proceed.
Wolfram tailing: xinhai will apply gravity separation, magnetic separation and flotation separation to recycle the wolfram. The gravity separation is commonly used. Wolfram tailing re-selection process is mainly used spiral chute and centrifugal ore separator to roughing, shaking table and flotation to cleaning.
Phosphate tailing: siliceous collophanite mainly include quartz siliceous minerals in gangue mineral, so the floatability of gangue is larger than valuable mineral.
Graphite tailings：xinhai will use the process of stage grinding and screening to recover the graphite from tailings. In the process of separation, flotation and shaking table is always used. If we want to achieve comprehensive recovery of several kinds of minerals from graphite tailings, we should combine several separation methods.
Bauxite tailings: when deal with the bauxite tailings, flotation separation and magnetic separation is the common process. Moreover, wetting, dry-tailing stacking and mine filling is always used.
There is a forty-year gold plant in Inner Mongolia. In 2002, before the construction of new tailings pool, the gold tailings in the old tailings pool was over 900 thousand ton. The gold content was about 1,665kg, while silver content was about 25t.
Xinhai practice tailings re-processing line in pulp-in-carbon factory, capacity was 300t/d, recycled gold and silver by using Gold CIP Production Line. In order to improve the target, xinhai applied negative oxygen machine instead of a vacuum pump, and adopted leaching while absorption process. After the process of gold loaded carbon desorption, pregnant solution electrodeposit, the gold concentrate is produced. The indexes comparison as follow: before reformation, gold and silver concentrate grade is 2.83g/t, gold leaching rate is 86.5% while silver is 48%. Finally, gold recovery rate is 80.4% while silver is 38.2%. The process fully exploit the value of tailings and enhances the efficiency of plant.