1. What is aggregate?
Aggregate is granular loose material which plays a role of skeleton or filling in concrete. Application of aggregate in Civil Engineering: cement concrete, asphalt concrete, road foundation, railway ballast, mortar, etc.
2. How many types of aggregates can be classified?
Generally, there are two types of aggregate: (1) according to the size of aggregate, it can be divided into two types
Coarse aggregate: rock particles with particle size larger than 4.75mm, such as pebbles, crushed stones, etc;
Fine aggregate: rock particles with particle size less than 4.75mm, such as river sand, mountain sand, sea sand, etc.
(2) According to the density of aggregate, it is divided into:
Ordinary aggregate: the density is 2500-2700kg / m;
Lightweight aggregate: density is 0~1000kg/m, such as ceramsite, calcined shale, expanded vermiculite, expanded perlite, foam plastic particles and so on.
Heavy aggregate: density 3500-4000kg / m, such as iron ore, barite, etc.
With the definition and types of aggregate, let's talk about the processing technology and related production equipment of aggregate.
The whole sand production system consists of four parts:
Feeding system, conveying system, crushing system and screening system.
Feeding system: generally, vibrating feeder is used to supply stone;
Conveying system: belt conveyor or plate conveyor, etc;
Crushing system: the heart of the whole set of equipment, consisting of multiple crushers, crushing various ore raw materials into finished materials of required size, generally including jaw crusher, impact crusher, cone crusher, sand making machine, etc;
Screening system: circular vibrating screen or linear vibrating screen and other screening equipment.
The whole sand production process is as follows:
The bulk materials are sent to the jaw crusher for initial crushing by the feeder, and the crushed materials are sent to the fine crusher - impact crusher or cone crusher for secondary crushing by the conveying equipment. Then the crushed materials are transported to the screening equipment for screening, and the finished products that meet the particle size are sent to the finished product pile, and those that do not meet the requirements are sent back to the crusher for further crushing.
We can refer to these principles when designing the whole sand aggregate production process
① Multistage crushing;
② The treatment capacity is matched before and after the stage;
③ Transfer bin design;
④ The material size is matched with the front and back level;
⑤ More sieving and less breaking, more breaking and less grinding;
⑥ Determine the belt according to the output and transportation height difference;
⑦ Flexible site layout.
