The practical significance of power plant slag separation and the process flow and design scheme of slag dewatering, the successful case of slag dewatering process in the application of self-supplied power plant of Xinlianxin Fertilizer Company, the slag dewatering sieve has achieved zero discharge of slag water after production, and achieved energy saving effect. And economic and social benefits.
一、the environmental protection benefit and economic benefit of zero discharge of ash and slag in power plant
A large amount of raw coal will be burned out every day in a coal-fired power plant, and the waste after coal combustion is the powder coal ash, which contains the slag of 10-15%. These slag usually pass through the slag bailing machine at the bottom of the boiler, and the fly ash, which is unloaded with the dust collector, is mixed to the ash field after the slag breaker.
With the development of science and technology, the comprehensive utilization of fly ash slag has been further developed, and slag is one of the most popular and best-selling resources.
a、The slag contains more water slag, it can replace the steel slag as the mixture of cement factory, and the price of the slag is only about a fifth of that of the water quenched copper slag.
b、Because the slag contains a certain amount of smokeless coke, the calorific value of the slag is about 4000J/k. Sintered bricks can be mixed with clay to produce sintered bricks. The granularity of slag is uniform. In the brick making, the brick billet is flat and dried quickly without cracking, and the raw coal can be saved 150 l. per ten thousand sintered bricks produced by the slag.
c、Can be used as the orthopedics of various fly ash slag materials (such as fly ash aeration and dense block etc.), and can be used directly instead of yellow sand. It can also be used as filler in some roof insulation projects, and has achieved better economic benefit. The slag can be used as the raw material of the load-bearing layer such as the construction highway, the town road, the parking lot and so on. Generally, three slag (lime: stone: slag 1: 4: 5) or lime-ash (lime: cinder 2: 8) are used, the bearing layer thickness is between 0.3 and 0.5 mm. because it will not fly. No secondary pollution. Transportation and storage is very convenient. Every ton of fly ash slag used in road construction can reduce the cost of road construction. Two yuan.
The dewatering treatment of slag can save water and save energy to reduce ash occupation and protect environment. At the same time, it brings considerable economic benefits to the ash users, which can not be underestimated for the society and the ash production power plants.
二、Slag dehydration process
The slag dehydration system is mainly used to separate slag from water after dehydration of slag water mixture through dehydration screen equipment, and the slag enters the inlet of dehydrated sieve through slag pump or through height difference. The dehydration screen moves in a straight line from the inlet to the outlet of the material through two motors. The slag on the screen is automatically discharged, and the water is discharged from the bottom of the screen. The dry slag can be sent out through the belt conveyor or transported by car. Through the dehydrated slag, there will be no leakage in the course of transportation. The sieve water enters the settling pool and is used by settling and returning water.
The dewatering of slag by dewatering screen simplifies the original dewatering system of slag, reduces the occupation of dewatering system and reduces the running equipment. The utility model saves the power consumption of the plant, improves the safety and reliability of the operation of the slag dehydration system, and reduces the production cost.
In order to improve the comprehensive utilization efficiency of ash and slag, save water and electricity, prolong the use period of the ash field, and improve the comprehensive purpose of the environment around the ash field, the ash water after the dehydrated field is realized.
三、 Economic and reliability analysis of dewatering sieve in slag dehydration
The slag dehydration process has been successfully operated in Xinlianxin Fertilizer Plant. The dehydration screen is a solid-liquid separation equipment specially designed for slurry materials. The equipment runs in a straight line and uses gravity to separate slag from water automatically. The dehydration screen has the following characteristics:
1、 It can be produced continuously for 24 hours. It is reliable in operation, free of manual operation, and can be discharged automatically by slag water.
2、 Long service life of high strength structure, riveting and welding of section steel assembly, forming the main body of frame with no stress and high strength degree;
3、small area, compact structure, convenient installation and debugging, easy operation and maintenance, and convenient process layout of the system;
4、the treatment ability is big, the sieve "V" type design is designed to climb slope dehydration, the dry material water content is low;
5、 low investment cost, low operating cost, less energy consumption and less easily damaged parts.
To sum up, the dewatering screen can realize zero discharge of slag water in power plant slag dehydration, which is an economical and reliable dehydration equipment.