Magnesite drying machine

Magnesite drying machine:Light burning powder is produced in the Dashiqiao and Haicheng areas of northeastern Liaoning Province, China, due to abundant resources and a concentration of manufacturers. However, most of them are directly fired by coal or water and gas in vertical kilns, and the production process is relatively backward, making it difficult to ensure quality.

The three major problems that restrict the normal development of magnesite products are halogen reflux, frost reflux, and warping deformation:

1、 Magnesite is a block shaped material of varying sizes (with larger volumes) that is layered and fed into a vertical kiln. This means that at the same temperature, larger blocks are prone to undercooking, while smaller blocks are prone to overburning. Both undercooking and overburning directly affect the active content of magnesium oxide in the product. Underburned magnesium oxide has a low activity content and exhibits an early hydration reaction with water during product production, forming magnesium hydroxide that does not react with magnesium chloride. Its bending deformation curvature is twice as large as that of normalizing, and it also poses a hidden danger for halogen reflux. Overheated magnesium oxide exhibits slow or no hydration reaction during product production, and its bending deformation curvature is twice as large as that of normalizing. It belongs to heavy burned magnesium and is suitable for use as a refractory material. Due to the low activity of magnesium oxide caused by undercooking and overburning, the hydration reaction is slow or ineffective. Therefore, the hydration reaction continues for a long time after the product is demolded, releasing a large amount of heat. When the hydration reaction temperature is at its highest, it can reach 97 ℃, resulting in volume expansion and causing the product to warp, deform, and crack. Especially when manufacturing polystyrene sandwich panels, the high hydration temperature leads to severe thermal shrinkage of the polystyrene panels. According to actual measurements, the center of the 50mm thick core board has shrunk to 13mm, forming a hollow drum.

2、 Even if the size of magnesite blocks is uniform, it is easy to cause uneven calcination time for each block during layered falling and discharge in the vertical kiln. If the time is long, it will be overburned, and if the time is short, it will be undercooked. In addition, manual feeding and discharging make it difficult to have a strict control method, which inevitably leads to unstable quality of magnesium oxide.

3、 Because the active content of magnesium oxide decreases rapidly over time during inventory and transportation, especially in seasons and regions with high humidity, it is prone to the same results as under burning and over burning. However, our company, Northeastern University's "Dongda Powder Engineering Technology Co., Ltd.", has developed a new process for lightly burned magnesium oxide calcination, which adopts a process of first grinding and then dynamic calcination:

Magnesite drying machineFeatures:

1. Grinding first effectively increases the specific surface area of magnesite powder in contact with high-temperature gas during calcination, making it evenly heated and fully calcined. According to their experimental measurements, it can significantly increase the active content of magnesium oxide. Provided quality assurance for magnesite products.

2. The dynamic calcination process adopts gas and powder injection calcination, which is easy to control in temperature and can be adjusted between 700 ℃ and 900 ℃ to select the calcination temperature and complete the entire calcination process in an instant, overcoming the drawbacks of under burning and over burning. Ensuring product quality. In short, the quality system of lightly burned magnesium oxide must start from the source and optimize and improve the calcination production process. Only with high-quality lightly burned magnesium oxide can the quality stability of magnesite products be guaranteed. Effectively restrain the occurrence of warping and deformation in magnesite products.

The adoption of heat sources can be designed and matched according to your company's existing conditions and requirements. The wet material after flotation is about 200 mesh, and the filter cake after pressure filtration and dehydration contains about 25% water. The dried powder enters the powder dryer and then enters the calcination furnace. The calcined exhaust gas is then supplied to the dryer. This is a drying and calcination combination system that fully utilizes energy, has a high degree of automation, meets environmental standards, has good technology, and has won national recognition.

Specific process flow: