Study On The Dust Suppression Solidifying Agent Being Used In The Transport And The Piling Of The Bulk Minerals

The serious dust pollution and the materiel loss are the main problems during the transport and the piling of the bulk mineral materiel due to the effects of wind and the jolt of transport vehicles. In particular, the high dust concentration probably causes the occurrence of the dust explosion in the tunnel which the transport vehicle goes through. The paper studies the dust suppression solidifying agent, which mainly is used for solving the dust pollution and the materiel loss of the bulk coal pile and transport, as well the application the other bulk mineral materiel.The cross-link mechanism of PVA with borax, the graft copolymerization mechanism of PVA with acrylic acid and starch with acrylic acid and the catalytic oxidation of starch were studied. The properties of the dust suppression, the viscosity behavior, the permeability in the piling of coal and the temperature resistant of the solidified test pieces also were investigated. The laboratory scale and the pilot scale spraying tests were done. The main conclusions are: 1. The controllable viscosity and its stability were obtained in the processes of the graft copolymerization mechanism of the water-soluble polymer with multi hydroxyl groups under the suitable rough material match, initiating agent and the reactive conditions.2. Borax shows the notable cross linked action for the water-soluble polymer with multi hydroxyl groups. The mechanism of the borax increasing the solidification process of PVA and the consistency regulating of the borax for starch solution were made, which is used for increasing the formation solidify layer.3. The surfactant addition into the dust suppression solidifying agent can improve the wetting in the surface of coal and further increase the permeability.4. The oxidation temperature, the amounts of oxidant and the addition catalyst show the notable effects on the carboxylic group formation. The viscosity of the oxidized starch solution is subjected to the extent of oxidation the pasting condition. The viscosity of oxidized starch solution which was made under 10% NaOH (in proportion to starch quality) adding with 25% starch concentration increased rapidly along with the storage time, while the starch concentration increased 40%, the viscosity of oxidized starch solution increased extremely and eventually the gel was formed. The low concentration PVA solution shows the sound viscosity stability.5. The spraying tests show that dust suppression solidifying agent mainly made of PVA had good dust suppression layer and film formation, the addition of borax shortened the time of solidifying layer formation. The solidifying agent based on the graft copolymerization of PVA with acrylic acid and starch with acrylic acid show the fine cohesiveness for bulk coal, its big viscosity is the spraying disadvantage. The solidifying agent based on modified starch show the inferior film formation.