Method for preparing metallic tin and sodium silicate by utilizing high-silicon type cassiterite concentrate

Abstract

The invention discloses a method for preparing metallic tin and sodium silicate by utilizing high-silicon type cassiterite concentrate. The method comprises the following steps: mixing the cassiterite concentrate pretreated by oxidizing roasting-acid leaching with sodium carbonate in a certain proportion, and then pressing the mixture into block mass; carrying out reduction roasting at a proper temperature in a reducing atmosphere, then carrying out ball-milling and leaching, and carrying out filtering separation so as to obtain metallic tin residue and a sodium silicate solution. The method is simple in process flow, gentle in process condition, low in cost and environmentally friendly, and can be used for realizing efficient separation of tin and silicon in the high-silicon type cassiterite concentrate. And moreover, a byproduct sodium silicate is obtained, so that the comprehensive utilization of the high-silicon type cassiterite concentrate resource is realized.

Description

technical field [0001] The invention relates to a method for preparing metallic tin and sodium silicate by utilizing cassiterite concentrate, in particular to a method for preparing metallic tin and sodium silicate by reducing and roasting high-silicon type cassiterite concentrate, which belongs to non-ferrous smelting and chemical industry metallurgical field. Background technique [0002] Tin is one of the earliest metals utilized by humans and has a long history. From the Middle Ages to the beginning of the 19th century, the world’s tin production grew slowly, with an annual output of less than 10,000 tons; by the beginning of the 20th century, the annual tin output exceeded 100,000 tons; at present, the world’s annual tin production and consumption are maintained at 350,000 to 400,000 tons Ton. The cassiterite concentrate used for tin smelting can remove most of sulfur, arsenic, antimony, iron, lead, manganese, bismuth, tungsten and other impurity elements after oxidat...

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Problems solved by technology

However, there are still disadvantages such as long tin smelting time and high smelting temperature.

[0006] 4) The non-patent literature "physicochemical aspects of carbothermic reduction of cassiterite in the ionic melt, Russian Journal of Non-Ferrous Metals, 2009, vol.50, No.6, pp.596-599" reports the use of cassiterite and sodium nitrate , Sodium carbonate as raw material, low-sulfur coal as reducing agent, the method of preparing metal tin by strengthening reduction in molten state, but no production report has been seen so far

Its significant disadvantages are: the use of NaNO 3 Low melting point substances are roasted in a molten state, which not only requires high refractory materials for the roasting equipment, but also NaNO 3 It is easy to decompose and produce NO at lower temperature (380°C) x , when in contact with water vapor it will produce NH 3 Corrosive gases, pollute the environment, and seriously affect the physical and mental health of operators

Although with the development of fuming furnace volatilization technology, the tin content in slag has been reduced to less than 0.1%, but the environmental pollution caused by fuming furnace volatilization cannot be underestimated, especially in the roasting and reduction smelting of concentrates, rich slag Smoke and gas containing toxic substances will be produced during the vulcanization and volatilization process of the fuming furnace of the secondary mine

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