Method for industrially producing silicate phosphate from rice husk carbon

Abstract

The invention discloses a method for industrially producing silicate phosphate from rice husk carbon, which comprises the following steps of: smoldering and carbonizing rice husks to obtain rice husk carbon; performing acid digestion or acid firing on the rice husk carbon to obtain initial activated carbon; and performing dustproof and explosion-proof sealed packaging treatment on the initial activated carbon, and performing intermediate temperature, sub-high temperature and high temperature activation to finally prepare high-quality silicate phosphate and activated carbon. The method overcomes the defect of low yield of silicate phosphate prepared from the rice husk carbon in the prior art. The process method has the advantages of simpleness, reasonableness, convenient operation and high separation rate of carbon and silicon elements from the rice husk carbon, overcomes the technical barrier of intermediate and high temperature activation of the rice husk carbon, can directly produce the high-quality silicate phosphate and activated carbon from the rice husk carbon, effectively improves the economical and social benefits of the rice husks, can realize the concept of conservation, low carbon and economy, and provides a new way for agricultural industrialization.

Description

technical field [0001] The invention discloses a method for industrially producing silicon phosphate by using rice husk charcoal, and belongs to the technical field of thermal engineering and inorganic chemical industry. Background technique [0002] Rice husk charcoal refers to the product of rice husk carbonization, the main components are carbon and silica, and most of them are charcoal; rice husk ash is gray silica with many impurities. At present, the industrial production of silicon phosphate is mainly obtained by reacting the non-renewable mineral diatomite with phosphoric acid. On the one hand, diatomite is expensive, non-renewable, and limited by resources; on the other hand, the process and equipment are complex and energy The high consumption makes the price of silicon phosphate too high to be used in large quantities. At the same time, it causes great pollution to the environment. Since the 1980s, it was found that rice husk contained about 15% (weight ratio) of...

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Problems solved by technology

If the pretreated carbon powder is activated in a closed furnace or a metal container, the closed furnace is difficult to build (even cannot be sealed); conditions), even if this can be achieved, it will not be able to produce continuously due to the long heating and cooling time, so the output is low and the cost is high, which is not cost-effective

Second, when solid carbon powder is mixed with solid alkaline substances (such as KOH, NaOH), it is difficult to be uniform, so that the activation effect (mainly SiO 2 The effect of reacting with alkaline substances and the effect of separating the product from carbon) is very poor, resulting in low adsorption value of activated carbon and low quality of water glass, low output and loss of market competitiveness

Third, there are too many alkaline substances, so that the activation equipment is easily corroded and damaged (especially at high temperature), and it is also extremely unsafe

Fourth, the alkaline gas with such a high concentration (such as the melting point of NaOH is 318.4 ° C, NaOH gas is easy to be produced if the temperature exceeds this temperature), is very easy to pollute the environment (air, water, soil), which is strictly prohibited

Fifth, to consume so many alkaline substances, the equipment is easily damaged, and the environment is more likely to be polluted. The economic and environmental benefits of this product are not worth the candle

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