The pseudo-fluid characteristics of the gas–solid separation fluidized bed provide a set of feasible methods for the dry separation of coal. The equipment used in the development of dry separation technology is receiving increasing attention around the world, because it generates no pollution during the separation process. However, the industrial application of related technologies using multi-component, complex fluidization equipment has met with considerable resistance. In recent years, a series of advances and achievements has been made in the study of the structural design, fluidization characteristics, and coal separation performance of the gas–solid separation fluidized bed. With respect to the historical development of gas–solid separation fluidized equipment and related progress in basic theoretical research, this paper summarizes the recent developments of the common gas–solid fluidized bed, vibratory fluidized bed, and magnetically stable fluidized bed. We comprehensively investigate the factors influencing the fluidized bed, and identify some problems that must be addressed to further advance the large-scale industrialization of the gas–solid separation fluidized bed.

The distribution plate structure plays an important role in the stability of air dense medium fluidized beds (ADMFB). Optimization of the distribution plate structure can reduce the generation of large bubbles. In the present work, the influence of the distribution plate structure on the fluidization characteristics of fluidized bed with agitator was investigated. Two different feedstock samples with the size fraction of 25–13 and 13–6 mm were tested individually. The experimental results showed that the fluidized bed density fluctuation was relatively small and the dead zone of gas-solids fluidized bed was significantly reduced by adding the stirring device into the fluidized bed under the optimal working conditions. Through a study of the sorting test, it was revealed that the separation performance can be effectively improved. This indicates that there is an obvious interrelationship between the structure of distribution plate and other process parameters, which affects the fluidization characteristics of ADMFB.

Magnetic separation is an indispensable part of magnetic separation, and the dry magnetic separator can be selected under the condition of water shortage in China to ensure that our country can also be selected under the conditions of lack of some resources. The magnetic separator plays a role in improving the grade of ore, purifying solid and liquid materials, and recycling waste. With the application and development of magnetic separation technology, magnetic separation equipment is constantly updating and replacing, and dry magnetic separation has experienced remarkable technological progress over the past twenty years. There are many new ideas and techniques applied in magnetic separators. So far, dry magnetic separators have developed many different applications for mineral and coal processing, for induction roller magnetic separators for chromite. Cross-belt magnetic separator for removing harmful magnetic particles and paramagnetic particles. The lifting roller magnetic separator is used in the heavy mineral industry to separate garnet from monazite and rutile. Rare earth drum magnetic separator for fine feed dry magnetic separation sorting process and rare earth roller magnetic separator for zircon and rutile in heavy mineral sand industry. These magnetic separators have different applications, and the dry magnetic separator is also moving toward large-scale and easy-to-manufacture.

The physical and chemical changes of three different types of lignite during drying at temperatures from 80 to 180°C were investigated using a moisture meter and an infrared spectroscopy system. The results showed that the drying of lignite could be classified into two stages, namely, a fast upgrading stage where surface moisture was lost, and a slower moderating stage where internal moisture diffused to the surface and evaporated. Some unstable oxygen-containing polar groups in the lignite decomposed during the drying process, resulting in an increased contact angle and reduced wettability. With increasing temperature, the size of the micropores decreased and the number of mesopores increased. The decrease in the specific surface area and the increase in the pore size and pore volume were observed. In addition, the moisture readsorption characteristics of lignite were closely related to the previous drying process. The reabsorption capacity of the treated lignite increased with increasing pre-drying temperature, while an extremely high drying temperature degraded the pore structure of partial lignite, such as Shengli lignite, reducing its ability to reabsorb moisture.