3results about How to "Avoid occupational hazards" patented technology

The utility model relates to the technical field of coal powder sampling, disclose a flat -end coal powder sampling gun powder leakage prevention device, include: elastic sealing body and protective cover, elastic sealing body is equipped with first through -hole for sampling gun to pass through, its aperture corresponds with the outside diameter of sampling gun, makes elastic sealing body when being equipped with in sampling gun pipe outside, can be pasted with sampling gun, protective cover is horn -shaped, has the first opening of sampling mouth direction and the second opening of far from sampling mouth, first opening is greater than the second opening, elastic sealing body is detachably arranged in the protective cover, the axis line extension line of first through -hole is through first opening and second opening, when sampling, sampling gun is through first through -hole, through holding the protective cover and push to sampling mouth to extrude elastic sealing body, make its block the gap between sampling mouth and sampling gun. The device has good universality and sealing property, through extruding elastic sealing body makes it and sampling mouth close adhesion, effectively prevent coal powder leakage.

The external dust receiving device comprises a dust receiving box, a stirrer, a dust input port pipeline, a dust output port pipeline, an air filter and the dust remover, the lower end of the dust input port pipeline and the lower end of the dust output port pipeline both extend into the dust receiving box, the upper end of the dust input port pipeline is connected with the dust remover, and the lower end of the dust output port pipeline is connected with the air filter. The upper end of the dust output port pipeline is connected with the air filter, the stirrer is installed on the top of the dust receiving box, the lower end of the stirrer extends into the dust receiving box, a sediment drain outlet is formed in the bottom of the dust receiving box, an automatic water injection port pipeline is arranged on the top of the dust receiving box, and an electromagnetic valve is arranged on the automatic water injection port pipeline. Through the application of the external dust receiving device of the dust remover for removing the silicon monoxide dust, the silicon monoxide dust can be fully mixed with water to form slurry, so that the direct contact between the slurry and air is blocked, and the spontaneous combustion risk and the fire hazard caused by the oxidation heat release of the silicon monoxide can be fundamentally eliminated.

This invention relates to a method for deep removal of heavy metals in a wet-process phosphoric acid process, comprising the following steps: (1) using a straight-chain or branched alcohol as a raw material, reacting it with phosphorus pentasulfide to obtain dialkyl dithiophosphate, and then reacting it with metal oxides, hydroxides or salts to synthesize dialkyl dithiophosphate (DDP); (2) reacting the DDP with one or more of the following: phosphoric acid slurry containing heavy metals, dilute phosphoric acid, concentrated phosphoric acid, and residual acid from phosphoric acid purification, to generate a heavy metal complex precipitate. After the reaction is complete, the purified phosphoric acid is separated to achieve the removal of heavy metals. This method has low raw material costs, and the cadmium content after heavy metal removal of phosphoric acid is ≤2ppm with a removal rate ≥96%; the copper content is ≤0.5ppm with a removal rate ≥99.5%; the arsenic content is ≤5ppm with a removal rate ≥70%; phosphorus loss is ≤0.5%; no reducing agent is required, thus avoiding hydrogen generation; it has little impact on the decrease in phosphoric acid concentration; and no H2S is generated. It is suitable for the removal of heavy metals from wet-process phosphoric acid slurry, dilute phosphoric acid, concentrated phosphoric acid, and other systems, and can be directly integrated into existing production lines.