New process for purifying and manufacturing microcrystalline graphite product

Abstract

The invention discloses a new process for purifying and manufacturing a microcrystalline graphite product, which comprises the following steps: adding calcined lime and water into graphite ore of which the grinding fineness is -200 meshes and the pass rate is above 90 percent after fine grinding, stirring uniformly and making pH of graphite ore slurry containing the calcined lime above 9; adding water glass to stir, adding kerosene to stir, finally adding pine oil to stir, inflating and scraping to perform rough concentration, and collecting roughly concentrated fine ore and tail ore of graphite; adding water glass into the roughly concentrated fine ore to stir, adding kerosene to stir, adding pine oil to stir, inflating and scraping to perform primary fine concentration, and collecting finely concentrated fine ore; adding water glass into the primarily finely concentrated fine ore to stir, adding kerosene to stir, adding pine oil to stir, inflating and scraping to perform secondary fine concentration, and collecting flotation graphite fine ore; adding NaOH solution into the flotation graphite fine ore for mixing, roasting, washing with water to neutral, performing acid leaching with hydrochloric acid, washing with water, dewatering and drying to obtain a high-carbon graphite product with the fixed carbon content in the graphite up to 98.74 percent.

Description

Technical field: [0001] The invention relates to a graphite production process, in particular to a new process for purification and purification of a microcrystalline graphite product. Background technique: [0002] Graphite is one of the most important simple substances of carbon, which is formed at high temperature. It is abundant in nature and widely distributed in mineral deposits. Graphite has a typical layered structure, carbon atoms are arranged in layers, and each carbon is connected to three adjacent carbons at equal distances, and the carbons in each layer are arranged in a six-point ring. The carbon-carbon distance between the layers is 0.142nm, and the interlayer carbon-carbon distance is 0.340nm. The carbons in the layers are connected by covalent bonds, which also have the properties of some metal bonds, and the interlayers are molecular bonds. The physical properties have obvious anisotropy and conductivity. [0003] Graphite is divided into crystalline (fla...

AI Technical Summary

Problems solved by technology

And in the prior art, medium and low-carbon graphite purification production generally adopts flotation method to select, and the flotation agent of flotation method is very important, and there is undisclosed to adopt kerosene and terpineol oil (being commonly called as 2# in the current document) oil) report

The high-carbon purification of graphite is commonly used in the high-temperature electrothermal method and the alkali method of sodium hydroxide at a temperature of 700°C to 800°C. The former uses the high-temperature resistance of graphite to place it in an electric furnace and heat it in isolation from the air. The ash in the graphite is volatilized above 2500°C, thereby producing high-purity graphite of more than 99.9%. This process is complicated, and a large electric furnace is required. The important point is that when the purity of graphite reaches 99.93%, the purification limit has been reached, and the fixed carbon content cannot continue to increase

Alkaline purification using sodium hydroxide at a temperature of 700°C to 800°C, due to the reaction of impurities such as Si, Fe, Al, Ca, K, Na, Mg and other elements in graphite with sodium hydroxide at high temperature to form soluble Wash the water with a large amount of water to remove some water-insoluble substances. The reagents used in this method are strong alkali and strong acid corrosion. At the same time, the density of graphite is small and the floatability is good. It causes a large loss of products, and the increase of waste is not conducive to recycling, resulting in higher costs. At the same time, due to the defects of the process itself, the purity of natural graphite can only be purified to 98-99.8%.

In addition, the chlorination purification process of natural graphite disclosed in Chinese patent application number 94105051.3, this process is to use chlorine gas and bulk material layer to infiltrate or fluidize the way to carry out high-temperature chlorination under the action of catalyst and reducing agent in the reaction furnace. The process is complicated, and there are great potential safety hazards. The purity after treatment is only 98% to 99.9%. This process has not been industrialized, and no one in the industry uses it.

The purification and purification methods of the above-mentioned graphite products are relatively complicated, and are not suitable for the specific graphite minerals in Daejeon.

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