1、 With the increasing maturity and promotion of comprehensive utilization technology of fly ash in China, the comprehensive utilization of fly ash is no longer in line with environmental requirements, and the huge economic benefits of comprehensive utilization of fly ash have been reflected. In the southeastern coastal areas and some developed regions of China, there is even a shortage of finished fine fly ash products. The fineness value of the fly ash emitted by a large number of coal-fired power plants in China generally varies between 20% and 50% (325 mesh sieve residue), which does not meet the requirements of the first and second level ash specified in the standard (GB196-91). Generally, power plants use fly ash dry sorting technology to separate the raw ash into coarse and fine particles to obtain finished fine ash, which can achieve certain economic benefits. However, the sorted coarse ash (usually with a fineness value of around 65%) has not been fully utilized and is generally still discharged or sold at low prices, even becoming a burden for enterprises. By using a specialized ultrafine grinder for fly ash, the mixture mainly composed of raw ash or sorted coarse ash is finely ground to give it a certain degree of hydraulic activity, producing blended ultrafine ash that can be used to prepare high-performance concrete, achieving the goal of fully utilizing fly ash and creating greater economic benefits. The use of ball mills for fine powder grinding has been applied in the cement industry for many years, with mature technology and relatively serialized grinding products. Drawing on the principles and structures of various high-precision and high-yield cement grinding machines at home and abroad, the research department of Yancheng Yanfu Environmental Protection Equipment Co., Ltd. has collaborated with the Materials Science Department of Nanjing University of Technology, a domestic university specializing in the comprehensive application of fly ash, to successfully develop a ball mill specifically designed for fine grinding of fly ash. This mill can finely grind the raw or coarse ash emitted from coal-fired power plants to achieve the fineness of finished ash. An additional sorting device is installed after the ball mill to sort the coal ash that has been ground by the ball mill. After sorting, the coarse ash is returned to the ball mill for ultrafine grinding, producing admixtures (micro powders) that can be used to prepare high-performance concrete. This greatly improves the economic benefits of comprehensive utilization of fly ash and enables the full utilization of fly ash. 2、 Overview of series fly ash grinding system 1. Introduction to grinding system process YGM series fly ash ultrafine ball mill system mainly consists of raw ash silo, auxiliary material silo, screw feeder, electronic measuring scale, fly ash special ball mill, powder selector, air box pulse bag dust collector, induced draft fan, screw conveyor, bucket elevator, feeder, control system, etc. The system directly retrieves ash from the raw ash bin, feeds it through a spiral feeder, and is electronically weighed before being transported by an air chute into the grinding head elevator. The elevator feeds the sorted coarse ash into the powder mill for pre grinding sorting. The sorted coarse ash is then sent into the feed inlet of the mill through an air chute and enters the ball mill for grinding. The material after grinding by the mill contains a large amount of fine ash, which is then fed into the powder mill for sorting by the elevator. The sorted fine ash is sent to the finished ash bin through subsequent conveying equipment. The tail of the mill is equipped with a dust collection system for dust collection. Compared with the open circuit (no powder selection machine) system, this closed-loop grinding process can increase the hourly output by more than 30-40%, making it an ideal equipment for deep processing of fly ash. 2. Process diagram of grinding system (attached) Working principle: YGM series fly ash mill is composed of working parts such as feeding part, cylinder part, and discharging part, as well as transmission components such as bearing seat, large and small gears, reducer, coupling, motor, electric control part, etc. 3. The ordinary ball mill is transformed into the YGM series fly ash special grinder. The grinder cylinder is generally divided into two compartments. Based on the particle size composition and grindability of fly ash or coarse ash and mixture, the internal device of the ball mill is modified for fly ash special ultrafine grinding: the YGM series propeller shaped fly ash grinding special double-layer screen partition compartment plate produced by our company is used to systematically transform the ball mill, making it more suitable for the closed-loop production process of fly ash grinding. YGM series propeller shaped fly ash mill double-layer screen partition compartment plate parameters: ⑴ grate plate, perforated guard plate: casting material: manganese chromium alloy?? Grille gap: 5mm ⑵ Screen frame: specially designed for fly ash grinding, made of imported wear-resistant steel plate; ⑶ Screen plate: Stamped part material: δ 3mm stainless steel?? Screen gap: 1.2-1.5mm (4) Standard parts: (cylinder and screen frame connecting bolts, nuts) depending on the specifications of the grinder. Specific modification measures: (1) Replace the original partition plate with a double-layer screen partition plate for fly ash, with a 5mm grid gap and a 1.2mm stainless steel screen gap in the middle. This can effectively control the particle size entering the second compartment, accelerate the introduction of qualified particles from the first compartment into the second compartment for efficient grinding, and reduce over grinding in the first compartment. (2) The length of the first compartment of the grinder is determined based on the grindability and moisture content of the fly ash. Usually, steel balls with a diameter of 20 to 50 are used for ball matching in the first compartment, and small size steel forgings with a diameter of 8 to 16 are used in the second compartment. Due to the relatively large surface area of micro forging, it can efficiently grind fine particles. At the same time, reducing the diameter of the grinding body can delay the flow rate of the material inside the grinder, increase the residence time of the material in the grinder, and strengthen grinding Adding activated lining plates in the tail compartment of the mill can effectively slow down the flow rate of materials in the tail compartment, enhance the grinding function of the small forging, and increase the specific surface area of the product The tail grinding discharge grate plate is a special discharge grate plate with a small grate gap of 5mm (which can be modified on the original basis), and the diameter of the lifting plate is adjusted to control the material grinding flow rate. The reverse end face of the double-layer compartment plate adopts a protective plate with ventilation grates, which not only protects the stainless steel sieve plate from being eroded by the grinding body, but also strengthens the ventilation inside the mill, promotes the timely discharge of qualified fine powder from the mill, and reduces the phenomenon of over grinding Choose an appropriate ventilation speed inside the mill, with a suitable wind speed of 0.8-1.0m/s, to shorten the residence time of qualified fine materials in the mill, promote the timely discharge of heat generated by micro powder and grinding, and improve grinding efficiency A flap locking device should be installed at the tail grinding and feeding area, and the locking device should operate flexibly. Generally, the circular flow process is adopted, which can significantly increase the system's hourly output, reduce the power consumption per unit product, and lower production costs. The mill adopts a pulse bag filter for dust removal, and the fan motor adopts variable frequency speed regulation to adjust the wind speed inside the mill, control the material flow rate and fineness. 3、 Installation instructions: 1. Installation foundation instructions: (1) This type of grinder must be installed on a solid reinforced concrete foundation that has already dried. (2) The foundation must not have significant tilting or sinking, and any slight sinking should be balanced and horizontal. Otherwise, installation cannot proceed. (3) The foundation and ground level of this type of grinder should have sufficient height for replacing liners and grinding media. (4) The basic design can refer to our company's foundation drawings. But this drawing cannot be directly used as a foundation construction work drawing. 2. Preparation before installation: (1) Before installation, all parts and components must be cleaned of rust proof oil and protective materials on their machining surfaces, as well as dust and dirt that may have fallen during transportation. (2) Inspect all machining surfaces and threads, and eliminate any defects that may occur during transportation and handling. (3) The assembled components should be carefully inspected. If any parts are found to be damaged or lost during transportation and storage, the defective parts must be repaired or replaced, and the missing parts must be completed. (4) During installation, the contact or connection surfaces of the parts should be lubricated. Dry oil should be used for fixed surfaces, and thin oil should be used for movable surfaces. (5) Before installation, all grooves and pits on the foundation should be cleaned thoroughly, and the surface of the cement poured at the end should be free of oil stains. (6) The installation should protect the friction surface and should not be cleaned with cotton yarn or unclean oil. The parts that are prone to dirt on the processing surface should be covered with special protective plates and clean canvas covers. 4、 Technical parameters