Lignite is a crude form of coal,which is peat by diagenesis formed humic coal, low degree of coalification, brown, dark brown, dark or asphalt luster,no caking.Its physical and chemical properties between peat and bituminous coal.High moisture, large volatile matter,small density, containing humic acid, oxygen content is often 15 ~ 30%, easy weathering fracture in the air, spontaneous combustion in the air.According to Chinese coal classification standard is divided into two small categories: light transmittance PM 30-50% of old age lignite and PM less than or equal to 30% of young lignite.China and Indonesia lignite are elderly lignite.
Dingli engaged in coal, coal slurry drying industry for many years, through the physical and chemical properties of coal and lignite drying temperature, pressure, air speed and oxygen quantity such related parameter research,Dingli establish lignite dryer test base in Inner Mongolia, after many experiments demonstrate technology research, successfully developed for lignite drying and lignite upgrade equipment. Our company lignite dryer can reduce the moisture of lignite 25-60% to 15-30%, after processing the calorific value of coal can reach 30-80%, direct as a substitute for thermal coal, bituminous coal and anthracite used in power plants.The technical equipment through has been running in China's Inner Mongolia, yunnan, xinjiang and Indonesia,it is security, stability, energy conservation, environmental protection,which has a huge and potential market, suitable for various coal mining enterprises.
The drying and dewatering process of lignite dryer is complicated, and the drying process must be selected according to the physical and chemical properties of lignite, so that the movement of lignite during the drying process is stable or rolling, and the evaporation surface is constantly changed, which is conducive to the rapid evaporation of water and safety.
The drying process of lignite dryer is similar and different from that of other minerals. According to the principle, lignite can be regarded as preheating section or accelerated drying section when it meets with high-temperature flue gas immediately after it is dried. The medium temperature is not beneficial for more than 600℃, and the time is about 5 minutes.
Water evaporated, and then go in constant speed drying stage, for the most part heat from hot air used in the evaporation of water, surface water evaporation, water from the dry material inside to outside move, to continue the amount of evaporation, the evaporation of water per unit time is more, by dry material temperature basic remain unchanged, the overflow between water surface evaporation and their internal water out of balance, material surface temperature was dry, and gradually narrowed, hot air temperature in hot conditions and the evaporation of water in the dry material balance, as a slow drying stage, until the end of the drying process.
The petroleum coke dryer project built by our company in Changsha, Hunan Province has been installed and officially put into operation.
The clean coal dryer project constructed by our company in Shenmu, Shaanxi has been installed and officially put into operation.
The raw coal dryer installation project undertaken by our company in Yumen, Gansu has been completed and officially put into production.