Aggregates, as one of the main construction materials, are widely used in the fields of water conservancy and hydropower, construction, high way, and railway etc. The aggregates qualities directly influence the strength of concrete. In this text, we will talk about the production line design, equipment selection and technological process.
I. Because of many uncertain factors of raw materials, the aggregates production line is differ from the cement production line in technology design. At present, when design the large scaled aggregates production line, we should based on making the optimized grading aggregates, saving the maximum binding materials to ensure the finished concrete with reliable quality and low comprehensive cost. On this basis, confirming the relevant production technological process to make sure the quality and capacity of finished products.
II. After deciding the aggregates, the production technological process is to be solved. The production system is mainly to solve the relationship of raw materials, technological process and equipment selection so as to solve the design problems. The main production phases of aggregates are mining, crushing, screening and sand making. The production technology includes open circuit and closed circuit. Furthermore, according to the finished products requirement, crushing ratio and raw materials particle size, the production process normally include two section crushing with sand making, three section crushing with sand making, also include secondary and third screening.
III. The aggregates production line normally choose the equipment according to the materials characteristic, system scale, site condition and technology. The main types of equipments are: crushing equipment, classifying equipment, conveying equipment, feeding equipment, and auxiliary equipment like power supply.
In the aspect of crushing materials, it can be classified into two types according to the working principle: one is impacting crusher, like vertical impacting crusher, impacting crusher and hammer crushing. The features are as follows:
1. Large crushing ratio;
2. Simple structure, easy maintenance;
3. Good grain shape, less compressive strength loss.
The other is laminating crushing equipment, like jaw crusher, cone crusher, which is suitable to crush the raw materials with high abrasion index, and low rock flour content. But the crushed materials have more flat and elongated particle and bad pumping performance.
Aggregates belong to regional materials, which are suitable for short-distance transportation. With the adjustment of national policy, the local government is more and more strict to the environmental protection, so the extensive form production line can not meet the development requirement. The development tendency should be large-scaled enterprises integrate the resource mines, to make full use of the advantages of the abundant financial resources, low energy consumption, and high efficiency, relying on the internal technical strength and management experiences to effectively exploit the resources.