Process for increasing carbon content in concentrate by removing impurities from graphite ore. Graphite is a kind of non-metallic minerals with many excellent properties. High temperature and chemical stability make it an important raw material for refractories. In addition, in the chemical industry, machinery, electronics, atomic energy and other fields have important applications. The morphology, can be divided into graphite flake graphite (graphite) and amorphous graphite (aphanitic graphite, earthy graphite). Flake graphite crystal 1%26mu; m, generally 0.05 ~ 1.5mm. The ore grade is low, the associated mineral mica, feldspar, quartz, tremolite, diopside garnet, rutile, sometimes with vanadium mica and other useful components. Amorphous graphite crystal size is less than 1%26mu; M. Its performance is not as good as that of flake graphite, and its industrial application scope is small. Ore grade is generally higher, but poor selectivity. Associated minerals include andalusite, hydromica, sericite, pyrite, tourmaline, etc.. Graphite concentrate products are divided into high purity according to different carbon content (carbon 99% ~ 99.99%), high carbon (carbon 94% ~ 99%), carbon (carbon containing 80% ~ 93%), low carbon (carbon containing 50% ~ 79%) four types of graphite. All types are classified according to size. With large scale, high carbon content for the best. Amorphous graphite is divided into graphite powder and graphite particle. The graphite used for refractory material shall be of high purity, high carbon and medium carbon graphite. China is a country rich in graphite deposits. The main producing areas are Shandong, Heilongjiang, Inner Mongolia and other provinces and autonomous regions. The world's Graphite producing countries are mainly Madagascar, Russia, India, North Korea and other countries.

(一)Method for processing graphite ore dressing

1.Processing method of 1 crystalline graphite

The natural crystalline graphite good floatability, in Chinese are basically using the flotation method for processing. Because of the size of graphite flake is one of the most important quality indicators, the method of multi - stage grinding and multi - selection is adopted to select large scale graphite as soon as possible. The common collector for flotation is kerosene, diesel oil, etc., and the foaming agent is two oil, No. four oil, and the adjusting agent is lime and sodium carbonate.

2 The aphanitic graphite processing method

Aphanitic graphite crystal is extremely small, so also called graphite, graphite particles are often embedded in clay, the separation is very difficult. Because of the high grade ore (containing carbon 60%-80%), so many graphite mines will be mined ore directly for grinding and processing, the sale of graphite powder products.

3 Purification of graphite products

The requirements of the modern industry for graphite products to two areas: first, the requirements of large crystal scales to achieve high purity, and the two is required to achieve ultra fine graphite particles (such as less than 1 m or 0.5 m). Chinese selected factory has established graphite purification and fine powder production line in the South and North villa villa, Liu Mao, Xinghe graphite, purification is the main method of chemical purification. The most mature technology of graphite and graphite by caustic chemical purification is melting at 700 DEG C, after washing to neutral, adding hydrochloric acid, washing, so that the graphite carbon content reaches 98% ~ 99%. There are also manufacturers of production of high purity graphite using hydrofluoric acid treatment. Graphite concentrate carbon content is generally 85% to 93%. In order to obtain high purity graphite, it needs to be purified. The purification methods include chemical purification, high temperature purification and mixing. The commonly used chemical purification is adding NaOH in the concentrate, the temperature at 500 degrees Celsius above the silicate mineral concentrate into soluble silicate, the water removed, then at room temperature with the hydrochloric acid dissolution of metal impurities. High temperature purification is the graphite placed in a special furnace to isolate air heating to 2500C, where the impurities are evaporated.

(二) graphite beneficiation process

1 crystalline graphite beneficiation process

Flotation is one of the main methods of graphite dressing, but the flotation of flake graphite is different from that of amorphous graphite. Graphite flake should be paid attention to in the process of flake graphite. Flake graphite flake graphite ore flotation selected is low, generally 4% to 15%, but the floatability is very good. Attention should be paid to the protection of scale in mineral processing,. The multi stage grinding and multi segment classification, one using 3 three 6 stage regrinding. The commonly used foaming agent for flotation is No. two oil, four oil, ether alcohol, butyl ether oil and so on. The collector is kerosene, diesel oil, heavy oil, sulfonic acid ester, sulfuric acid, phenol, carboxylic acid and so on. Amorphous graphite ore dressing amorphous graphite raw material of high grade, generally 30% ~ 90%, but due to the size of graphite embedded cloth fine, but it is difficult to improve the grade. Collector, camphor oil, pine oil as frother, sodium carbonate as a modifier used for flotation of coal tar, water glass and sodium fluosilicate as inhibitors. Beneficiation process of flake graphite beneficiation process includes: (1) preparation (coarse crushing and coarse grinding); (2) the flotation operation (roughing, scavenging and cleaning); (3) concentrate treatment dehydration, drying, grading and packing). Graphite ore hardness medium soft, crushing process using open circuit crushing. The flotation process for multi stage grinding and multi segment classification, middling order (or concentration) closed process of return.

2 The aphanitic graphite beneficiation process

Although the aphanitic graphite ore grade is high, but it is difficult to separate. In China, it is usually mined graphite ore after a simple hand, directly crushed into a product for sale. The general process is: the crushing, crushing, drying, grinding, and classification, packaging.

三)common technical equipment

Amorphous, amorphous graphite ore crushing by jaw crusher, crushing, the cone crusher and hammer crusher, grinding by ball mill, spiral classifier, classifier using high frequency sieve and hydrocyclone flotation used SF type flotation machine. The flotation of graphite powder dry powder obtained by drying and drying machine.

(四)Quality requirements of graphite:  

Graphite ore dressing method, graphite ore dressing technology, Graphite ore dressing process