Research on the coupling diffusion law of airflow-dust-gas under the modularized airflow diverging dust control technology

Preparation and performance of starch-based cross-linked network structured dust suppression foams for complex climatic conditions

In complex environmental applications such as rain erosion and high-low temperatures in open-pit coal mines, the curing layer after dust suppression foam treatment is relatively poorly tolerated, resulting in poor dust suppression. This study is aimed at a high-solidification strong weather-resistant cross-linked network structure. First, oxidized starch adhesive (OSTA) was prepared by the oxidative gelatinization method to reduce the effect of the high viscosity of starch on the foaming effect. Then, OSTA, polyvinyl alcohol (PVA) and glycerol (GLY), were copolymerized with the cross-linking agent sodium trimetaphosphate (STMP), and compounded with sodium aliphatic alcohol polyoxyethylene ether sulfate (AES) and alkyl glycosides (APG-0810), a new material for dust suppression in foam (OSPG/AA) was proposed and its wetting and bonding mechanism was revealed. The results show that OSPG/AA has a viscosity of 5.5 mPa·s, a 30-day degradation of 43.564 % and a film-forming hardness of 86HA; through simulated tests in open-pit coal mine environments, it was found that the water retention of OSPG/AA is 40.0 % higher than that of water, and the dust suppression rate of PM10 is 99.04 %. The cured layer can adapt to temperature changes from -18 °C to 60 °C and remains intact after rain erosion or 24 h immersion, exhibiting good weather resistance.

Preparation and properties of modified starch-based low viscosity and high consolidation foam dust suppressant

Aiming at the high-concentration dust pollution in open-pit coal mines, a foam dust suppressant with low viscosity and consolidated coal dust is developed. In order to reduce the limited effect of binder viscosity on the foaming ability and wettability of foam, tapioca starch is oxidized with Cu²⁺/H₂O₂ System in this study to reduce the molecular weight of the polymer and prepare materials with high consolidation and low viscosity. The dust suppression performance of the sample is measured, and the microscopic adsorption mechanism of the dust suppressant is investigated by molecular dynamics simulation. The results show that the oxidized starch adhesive solution consists of 20 g tapioca starch, 0.88 ml hydrogen peroxide, 2.4 g sodium hydroxide, and 0.48 g copper sulfate, which need to be diluted to 10 times the original volume, and 1 g of surfactant (sodium fatty alcohol polyoxyethylene ether sulfate/alkyl Glycoside=1:4) is added to prepare a new foam dust suppressant. The viscosity is 2.6 mPa·s, the foaming multiple is 6.25, the contact angle is 13.73° at the first second, the hardness reaches 70.75 HA, and a dust suppression rate of 98.17% for PM10. The dust suppressant can effectively suppress coal dust.

Development and characterization of a high efficiency bio-based rhamnolipid compound dust suppressant for coal dust pollution control

Surfactants make a significant contribution to the suppression of coal dust fly in underground coal mines, but are hazardous to the environment and human health. It is therefore crucial to develop more environmentally friendly and efficient wetting agents using non-polluting eco-friendly surfactants. In this study, the wetting properties of the biosurfactant rhamnolipid were investigated and the rhamnolipid composite wetting agent (CS-A-S) was prepared by mixing design after preferring different surfactants by means of experiments and quantum mechanical simulations. The dust suppression properties were compared by means of infrared spectroscopy, scanning electron microscopy and molecular dynamics simulation. The results showed that the critical micelle concentration (CMC) of rhamnolipid was 0.04 wt% and the surface tension was 25.9 mN/m, which had the basis to become an underground dust suppressant; the surface tension of CS-A-S was reduced to 23.95 mN/m and the contact angle to coal dust was 25°; after spraying CS-A-S, the median particle size of coal dust reached 125.76 μm, an increase of 849.13%; the specific surface area was reduced to 2.24 m²/g, a decrease of 51.06%; the oxygen-containing groups on the coal surface increased by 55.87-246.7%, making it easier to form hydrogen bonds, the coal dust became more hydrophilic, and coal dust particles easily agglomerated into larger sizes and settled rapidly under gravity; the CS-A-S simulated system showed the greatest degree of water molecule penetration, with a minimum of 71 Å, and a water molecule diffusion coefficient of 1.06 Ų/ps, a decrease of 75%, and the interaction energy with coal molecules is 155.6 kcal/mol, an increase of 66.9%, making it easier for the dust suppressant molecules to form adsorption on the coal surface, showing a better dust suppression effect.

Synthesis and performance determination of a glycosylated modified covalent polymer dust suppressant

Traditional polymer dust suppressants are limited due to environmental pollution, while polymer gels have attracted attention due to the advantages of environmental protection and good biocompatibility. The purpose of this research is to prepare a new type of dust suppressant with a gel network structure, which was synthesized from soybean protein isolate and glycosylated with xanthan gum. The experimental results showed that the product obtained by reacting 0.2 % xanthan gum and 0.1 % soybean protein isolate at 90 °C for 4 h has the best binding effect on coal dust, and the coal husk hardness can reach 83 HA. The microscopic reaction and structure of the product were analyzed by infrared spectroscopy, X-ray diffractometer, and scanning electron microscope, and the results revealed the structural change and specific reaction process of the product. In addition, through molecular dynamics simulation, the dust suppression effect was confirmed and the mechanism of action between dust suppressant and coal was revealed. The performance test of the dust suppressant showed that its viscosity is 23.4 mPa·s, the contact angle at 1 s is 10.01°, the PM10 dust suppression efficiency can reach 98.10 %, the water retention is 44.44 % higher than that of water, and thermal stability is improved.