Preparation method of superfine basic copper nitrate for gas generator

Abstract

A preparation method of superfine basic copper nitrate for a gas generator comprises the steps: 1, preparing aqueous solutions of cupric nitrate trihydrate and sodium hydroxide; 2, adding the sodium hydroxide aqueous solution and an additive into a reaction kettle, uniformly adding the copper nitrate aqueous solution into the reaction kettle within 0.5 h, controlling the pH value of the reaction solution of 7.5-9.0, and with the temperature of 60-90 DEG C, carrying out a reaction for 0.5-3 h; 3, carrying out filtration of a precipitation, retaining a mother liquor, adding water into the precipitation, pumping the suspension of the precipitation into a spray dryer for spray drying, and then packaging; and 4, pumping the mother liquor into a vacuum evaporator, carrying out reduced pressure evaporation, carrying out cooling crystallization, filtering, and drying the crystals for package. The crude product which can prevent aggregation or can prolong the time required to aggregate is obtained, and the steps of centrifugally spin-drying and multiple-time washing, levigating by a coarse powder machine and further crushing by an airflow crusher are omitted, so that the time is saved, the equipment investment is saved, moreover, the energy consumption and environmental pollutions are also reduced, the cost of the product is reduced, and the product can reach a same granularity level by a traditional process.

Description

technical field [0001] The invention relates to a preparation and production process of ultra-fine basic copper nitrate for an automobile airbag gas generator. More specifically, it involves the reaction conditions (pH, temperature, reaction time, concentration, additive type, etc.) for preparing ultrafine basic copper nitrate by precipitation method, the drying method used for the product basic copper nitrate, and the entire process flow. Background technique [0002] Automobile airbag is composed of generator and airbag. The gas generator is equipped with a gas generating agent, and when the vehicle collides with a certain strength, the gas generating agent is ignited to generate gas to fill the air bag. At present, the most used gas generating agent is the guanidine nitrate type gas generating agent. This gas generating agent uses guanidine nitrate as the fuel and basic copper nitrate as the main oxidant. The amount of basic copper nitrate can generally account for 15%-...

AI Technical Summary

Problems solved by technology

The first disadvantage is that the process is complicated and consumes a lot of power

Taking a 20kw coarse powder machine and a 50kw jet mill to crush 300 kg of basic copper nitrate as an example for 8 hours, then to produce 1000 tons of ultra-fine basic copper nitrate requires 1,866,667 kilowatt-hours of electricity. The second disadvantage is that the material loss is serious during the crushing process, and generally more than 10% of the raw materials will be lost after the two-step process is completed; the third disadvantage is that it is not environmentally friendly, because the dust is too large, it will pollute the human body and the surrounding environment, and The installation of dust removal equipment will increase the equipment cost of the enterprise, which is generally unaffordable for small enterprises

In addition, the washing and centrifugal drying process before crushing will produce a large amount of water containing heavy metal elements, and the pressure on environmental protection is also great.

More importantly, the basic copper nitrate obtained by the reaction of copper nitrate trihydrate and sodium hydroxide originally has a very small particle size, but due to the serious agglomeration between the basic copper nitrate particles, the particle size increases, and centrifugal filtration will This agglomeration effect will be increased even more, which will bring trouble to the subsequent crushing

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