China's poor chrome ore dressing, have adopted Lean chromium jig, shaker, spiral separator, centrifugal concentrator over (Cr203 < 20%), also use hydraulic sorting sorting have table. In the laboratory, the dry strong magnetic separation, wet high intensity magnetic separation, flotation and various chemical beneficiation methods were studied. But in the actual production mainly uses the gravity method.

Chromite ore processing method and ore beneficiation process (ore beneficiation process):

Exploration of chrome ore mining of mineral resources, the various grades of mineral products, can meet the needs of production in different industrial applications. The mining method is determined by chromite ore deposit mining with dispersed form, often open, mainly for large underground mining seam. Most of the chromium content of higher ore without dressing; dispersion of the deposit after the selection can be obtained after chromium content is 50%. Besides the chemical grade and refractory grade ore is transported to the chemical factory and refractory material factory, chromium ferroalloy plant transported to the smelting high grade chrome alloy, as an alloying agent for iron and steel industry, or smelting metal chromium alloy used as additives, special. Because chromium is the most versatile metal, and in the "strategic metals" in the first place. The lack of a world of chrome ore resources of the country or resources of the country, are stepping up research of chromium ore, its separating method;

(1): Gravity dressing: such as heavy medium cyclone, jig, spiral chute, shaker, centrifugal separator.

(2): Magnetic separation and electric separation: Including the magnetoelectric high field strength magnetic separation, high voltage selection.

(3) Flotation and flocculation flotation.

4): Joint selection: such as the gravity of electric separation.

(5): Chemical beneficiation :Processing fine refractory lean chromium.

In the chromium ore beneficiation method and chrome ore dressing process (ore beneficiation process), production mainly uses the gravity method, often using hydrocyclone pretreatment run tail, spiral chute as roughing, selected, shaking do scavenging and then select centrifugal concentrator fine materials and then get the final separation of chromium the products with weak magnetic separator. Sometimes the gravity concentrate with weak magnetic separation or strong magnetic re-election, to further improve the chromium concentrate grade and chromium iron ore. High chromium spinel containing iron or magnetite ore symbiosis and dense, the concentrate obtained after, chromium and ferrochromium are lower than the grade, can be used as a production method of ferrochrome fire ingredients, or by hydrometallurgy. Such as sodium dichromate, chromic hydroxide method, reductive leaching, chloridizing roasting acid leaching or electrolysis. Treatment of lower iron concentrate has a production practice by hydrometallurgy.

In the chromium deposits associated with platinum (platinum, palladium, iridium, osmium, rhodium, cobalt, and nails) titanium, vanadium, nickel and other elements. When the platinum content is greater than 0.2-0.4g/t, the cobalt content is greater than 0.02%, and the nickel content is greater than 0.2%. Chromite ore in platinum group elements such as sulfide, was associated with arsenic or sulfarsenide, can use the flotation. The ore of olivine and serpentine, can be considered comprehensive recovery, for the production of refractory materials, calcium magnesium phosphate or diabase etc.. In the non crystal magnesite ultrabasic rocks in shallow and sometimes wearthering origin, refractory material is also very good.

At the end of 1960s has built the Shaanxi Hebei province Zunhua Shangnan chrome ore, chrome ore, chrome ore and other small plant of Beijing miyun. Since 1970s, the Inner Mongolia Ximeng Hoeg Aola chrome, Gansu Province, Tibet great gonchigdorj chrome ore and chrome ore, Xinjiang and other places for the study of ore dressing. Due to the lack of resources, China's chromium ore dressing has been in a backward state. Several small concentrators are only by single gravity separation (shaker) sorting poor chrome ore, such as Zunhua and Miyun, Shangnan concentrator of the cradle fine crystal size of poor chromium ore, the ore containing Cr2O34% ~ 20% were selected with Cr230%, -45%, the recovery rate is 62% ~ 82% of the fine ore

China Zhengzhou Jintai beneficiation equipment Co. Ltd., Zhengzhou tronickey Machinery Co. Ltd. joint research and development in chromium ore beneficiation methods and ore dressing process (ore beneficiation process) research has made great progress, a department of mechanical in a region with refractory stage grinding, spiral chute, the chromium ore grade increased by the 22.4% to 35%, the recovery rate is 80.18%, for easy selection using lean chromium jig, spiral chute, shaker, centrifugal concentrator combined flowsheet, chromium ore concentrate grade increased from 19% to 40%.     

Natural chrome ore, chrome ore and low silicon content of SIO2 is less than 2% is almost non-existent, must through the mineral purification can be obtained. Therefore, it is of great significance to study the process of reducing the silicon content of refractory grade chromite ore in the development of magnesium, aluminum, chromium series refractory.

Similar to Xinjiang Salto sea and Tibet red two chromium ore properties. The main mineral is chromium spinel, the content is about 85% ~ 90%, the particle size of chromium mineral is generally between 1 and 5 mm, the minimum 0.3-0.5 mm. The gangue minerals are chlorite, serpentine, with small scaly colloidal aggregates and fibrous mineral grains and chromium distribution in crack, maximum diameter of 0.15 mm * 0.075 mm, generally less than 0.008 mm. The ore properties, silicon containing minerals in the ore block cloth must be very fine, fine grinding to monomer dissociation. Using a grinding to 0.3 mm one or two spiral chute --- a centrifugal concentrator flowsheet, obtain good classification effect. When the content of CrO3 is 3365% and the content of Si02 is up to 6.01%, the content of can be obtained with low content of Crz0 and the content of is up to 37% and the content of so/ is low.

Tibet chrome ore: when the ore is selected, the content of Cr203 is 48.46%, the content of SiO2 is higher than that of, and the content of Cr203 can be obtained with the content of 53.26%.Si02 as high as 0.98%. From Xinjiang, after tons of continuous expansion test, obtained the concentrate containing Cr2O3 7.45%, SiO21.8%. The stage of the test room of Gansu great gonchigdorj chrome ore grinding jig three - segment shaking process when testing, from ore containing Cr2O3 32.56%, containing Cr20345.82%, the concentrate recovery rate is 96.68%. Experiments show that the stage grinding of Inner Mongolia Ximeng Hoeg Aola chrome one or two section shaking process, can be obtained with Cr2O34.18%, the rate of recovery is 77.45% from Cr2O322.41% containing ore concentrate. Chromite direct electric furnace steelmaking process for high purity chromium concentrate, the jig table a centrifugal separator combination process of two kinds of chromium ore grade deep, can obtain high grade and iron ratio, low content of harmful impurities of high chromium concentrate.

The factory original design process includes the following work: 100 ~ 10 ore level by two heavy medium (cylinder processing machine) processing, medium density of 2.7 ~ 3.31 g/cm3. Heavy medium separator middling crushing to 10-0mm and the 10 - 0 mm level with 10 ~ 3 storage to be selected; the mm and 3-Omm level respectively by jigging jig; middling regrinding products to 0.5 ~ 0mm after using spiral concentrator. 0.5 ~ 0 mm slime by tabling don't. In basic research, long time debugging on 1983 was improved: to improve the reliability of the jig sorting operation, installation of second standby series, greatly reducing the fault caused by factory production time. Efficient use of jigging machine to improve the jigging separation efficiency, especially in the 3 ~ 5mm level, instead of phi type 600mmm spiral concentrator with 1500mm diameter spiral concentrator jigging middlings regrinding, improve the physical separation rate of teaching. The separation of high field magnetic separator and spiral tail ore dressing recovery table 0.25mm in the mud. The process plant improved after.1983 years in the process index of yield and quality have reached and exceeded the design specification. When the ore in refractory disseminated ore ratio of more than the usual proportion (20% ~ 25%) to 30% -35% (up to 44%), the first paragraph must use the heavy medium separation, so that the design process can ensure the chromium oxide concentrates to content provided valuable components in the tailings and reduce the loss.

The process of chrome ore dressing method, chrome ore beneficiation technology, chrome ore dressing: