Other mineral processing techniques for spodumene

Hand-selected and flotation is the primary method of sorting spodumene, other methods such as thermal cracking process, magnetic separation, gravity separation and aid plays a minor role in the production of spodumene concentrate.

(1) Thermal cracking ore dressing method

The thermal cracking beneficiation method is a method of selecting a spodumene ore. The method is based on the natural spodumene calcination at about 1100 ° C, the crystal changes from α type to β type, while volume expansion, brittle into powder, which can be used to selectively grind and sieve to reach spodumene and gangue Separation of minerals. This method has been applied in the Canadian plant, China, and the Soviet test room. China's ore dressing workers have used raw ore containing 1.58% Li3O for testing. They were first calcined at 1050 °C for one hour, cooled and placed in a rubber ball mill for selective grinding. Finally, they were sieved with a 150 mesh sieve. The sieve concentrate has a grade of 4.9% Li2O and a recovery of 74%. The cane plant in Canada used the thermal cracking method to select the spodumene ore. The ore grade of the plant was 1.85% Li2O, and the obtained spodumene concentrate grade was 4.39% Li2O, and the recovery rate was 85%.

There are two points to be paid attention to when applying the thermal cracking beneficiation method: 1 control the roasting temperature above 1100 °C, when the temperature is too high, the mica present in the ore will be sintered; when the temperature is too low, the transformation of spodumene from α to β is incomplete. 2 The ore should not contain a large amount of minerals that are easily melted during calcination or other minerals with thermal cracking properties, otherwise the purpose of separating spodumene may not be achieved.

(2) Heavy medium beneficiation method

Since the difference in density between spodumene and associated gangue minerals is not large, re-election methods such as jigging, spiral beneficiation and shaker beneficiation are not suitable for the selection of spodumene ore. However, heavy medium ore dressing or heavy liquid beneficiation is an effective method for semenite ore. Heavy medium dressing has been used in the production of lithium mines in South Dakota and North Carolina. In South Dakota were prepared in a processing plant -200 mesh silicon iron weighting agent and the density was 2.7 g / cm 3 medium, heavy medium using a cone concentrator sorting plant of 3.3 to 3.8 mm spodumene ore, As a result, the produced spodumene concentrate grade reached a 5.31% Li2O operation recovery rate of 78%. In North Carolina Gold Mine wire except heavy medium beneficiation machine taper, used heavy medium cyclone sorting finer size range spodumene. Further U.S. Bureau of Mines with further beneficiation art tetrabromo ethane as the heavy liquid (density of 2.9529 g / cm 3) of the heavy liquid cyclone sorting of successive trials spodumene ore, quite satisfactory results are achieved, the feed size For -35 mesh, containing 20% ​​of lithium phosgene, the obtained concentrate contains 92~95% of lithium pyroxene, the recovery rate is 86~89%, and the recovery rate of heavy liquid is above 95%. As long as there is good protection, Tetrabromoethane can be used on a large scale.

(3) Magnetic separation method

Magnetic separation is often used as an auxiliary method to improve the concentrate quality of spodumene. For example, the spodumene concentrate produced by the flotation of the Jinsishan plant in North Carolina, USA, is high in iron and can only be sold as a chemical grade concentrate. In order to meet the requirements of the ceramic industry, the plant uses magnetic separation to remove iron. In addition, since iron-lithium mica has weak magnetic properties, magnetic separation can be used as the main method for producing iron-lithium mica concentrate.

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