A method for the recovery of nickel and energy substances from nickel hyperaccumulator plants

Abstract

The invention discloses a method of recovering nickel and energy substances from nickel hyperaccumulators. The method combines mechanical crushing, vacuum pyrolysis segmented condensation, heavy metalleaching and chemical precipitation. In the method, the energy substances, such as pyrolysis oil and pyrolysis gas, are recovered through a vacuum pyrolysis segmented condensation technology; pyrolysis residues are leached by adopting a mixed solution of hydrochloric acid and nitric acid; and nickel elements in a leaching solution precipitate in a form of nickel carbonate by adopting a sodium carbonate precipitant, and finally, a nickel carbonate solid is filtered and recovered. By adopting the method, high-value resource recovery of the nickel hyperaccumulator harvests is realized, biomassesof the nickel hyperaccumulators are converted to the energy substances, the nickel elements rich in the plants are recovered, and harms to the environment caused by exposure of the nickel hyperaccumulators to the environment is avoided; and the method is simple in whole process and high in recovery efficiency as well as has remarkable economic and environmental benefits.

Description

technical field [0001] The invention relates to the technical field of solid waste recycling, in particular to a method for recovering nickel and energy substances from nickel hyperaccumulation plants. Background technique [0002] Soil is the foundation of human survival, and most of the substances needed for human survival come from soil. However, since the industrial revolution, a large amount of soil has been polluted, which seriously threatens human life. Heavy metal pollution is particularly prominent in soil pollution. Since heavy metals cannot be decomposed by microorganisms in the soil, they are easy to accumulate in the soil, seriously endangering the health of humans and soil animals and plants. Heavy metal nickel is one of the eight heavy metals in soil pollution. Excessive nickel soil pollution can retard plant growth and cause plant necrosis. Long-term exposure of the human body to nickel will cause skin ulcers and even induce cancer. Therefore, some methods h...

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Problems solved by technology

However, the cost of this method is relatively high, and only nickel can be recovered by this method, and a large amount of biomass energy of the hyperaccumulator itself is completely wasted, and a large amount of toxic and harmful gases will be produced during the incineration process

[0004] In addition, the patent CN106987722A pyrolyzes the hyperaccumulated plant harvest, and the pyrolytic charcoal produced by pyrolysis is leached with the leaching solution to extract heavy metals, and then enters the fluidized bed together with the pyrolysis oil to generate gasification gas, but the pyrolysis produces The pyrolysis gas has not been well treated and recovered, resulting in waste of resources and environmental pollution

Patent CN106984628A uses pyrolysis, purification, electrochemical deposition, leaching and other methods to recover gas, bio-oil and metals after pyrolysis of hyperaccumulated plant harvests, but the process is complicated and the operating cost is high, so it is difficult to produce more great economic value

Patent CN109987973A adopts the method of incineration to burn Osmanthus superaccumulative plant harvest into ash and prepare ash and rare earth micro-fertilizer. However, a large amount of toxic and harmful gases will be produced during the incineration process. In order to obtain proper treatment, incineration is also a The waste of the biomass resources of Osmanthus persicae itself has insufficient environmental and economic benefits.

Patent CN109794262A adopts pyrolysis method to burn cadmium hyperaccumulated plant harvests into cadmium-containing biochar, and uses sulfidation reaction to prepare cadmium-containing biochar into carbon-loaded cadmium sulfide photocatalytic material, but does not produce cadmium sulfide in the pyrolysis process. Pyrolysis oil and pyrolysis gas are recycled, resulting in a waste of resources. At the same time, exposure of pyrolysis oil gas to the environment will cause environmental pollution, which in turn will cause harm to the human body

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