This paper introduces the process design of sand and stone production line.Date: 2019-06-26 Views:
First, the selection of mainframe equipment
Sand aggregate production line can be simply summarized as: crushing, screening and storage. In order to obtain aggregate products whose indexes are in accordance with the standard, the selection of mainframe equipment will be the primary consideration in the design of production line.
1. Selection of feeding screen equipment
Aggregate products have high requirements for soil content. In the design, a feeding equipment which can remove soil from the source is usually equipped before the material enters the rough break, so that the vibrating screen feeder has become a better choice.
When the soil content in the raw material is small and the raw material is dry, the size between the sieves of the vibrating screen feeder can be adjusted to the appropriate value, and the soil can be screened out after the material passes through the feeder.
When the soil content in the raw material is more or the raw material is sticky, it is necessary to consider slightly increasing the size between the sieves of the feeder. After screening, most of the waste containing soil (blocks) is screened clean through a round vibrating screen, and the stone on the screen of the vibrating screen can be broken back into the secondary crusher.
2. Selection of crushing equipment
It can be divided into two categories: extrusion crusher and impact crusher.
General extrusion crusher (e.g. cycle crusher, jaw crusher, cone crusher) is suitable for hard rock (such as granite, basalt, etc.);
Impact crusher(e.g. counter-attack crusher, vertical shaft crusher, hammer crusher)is suitable for rock with low hardness and poor abrasion(such as limestone).
Two typical aggregate crushing plant configurations are described below:
First, in view of hard rock, hardness and high wear index, the "jaw crusher conical crusher shaper shaping machine (that is, vertical shaft crusher)" was selected because the broken aggregate needle-like content of conical crusher was more, which did not meet the standard-GB/T 14685 shredder.
Second, for limestone, hardness, abrasion index is moderate, select``jaw crusher+reaction crusher'' or``reaction crusher+reaction crusher'' .
It should be noted that hammer crusher is rarely used in the production of sand and stone aggregate. Although the hammer crusher is a stage of crushing, the process is simple, but because of the low yield of bulk aggregate, easy to crush, many powder materials, the finished aggregate will produce microcracks, the compressive strength will be reduced, the quality of aggregate will be affected, and the sales will be affected.
3. Selection of screening equipment for finished products
In general, a circular vibrating screen is used for screening equipment in the aggregate industry of sand and stone. If you are concerned about the lower screen rate, you can select two finished vibrating screens.
II. Precautions for workshop layout 1. Selection of effective volume of receiving hopper in front of crusher.
In general, the effective volume of the hopper design should meet the following two conditions at the same time:
1)Not less than the continuous operation of the crusher for 12~15min;
2) Not less than 3 transport vehicles.
2. Arrangement of crushing workshop
The arrangement of crushing workshop should not only take into account the smooth incoming and outgoing materials in the crushing process, but also make full use of the terrain height difference to make full use of the terrain height difference, and put the crushing machine cloth in the ±0.000 plane of the workshop as far as possible. In this way, it can not only reduce the investment of civil construction, but also provide a lot of convenience for crusher maintenance, inspection and replacement.
1) the layout of vibrating screen should be designed and inspected around its equipment;
2) the workshop should be closed and the vibrating screen equipment itself should be sealed in order to avoid a large number of dust spills during screening;
3) the dust collection treatment of the dust-containing gas is facilitated.
4. Layout of finished material yard
In response to the national environmental policy, the finished aggregate can be stored in a stack or depot. In the storage of the stacking shed, to reduce the secondary dust of the forklift truck, if the terrain elevation difference is available, the loading belt conveyor shall be designed as far as possible.
III. Environmental protection matters 1, environmental pollution sources
The pollution of the sand and stone production line to the environment is mainly dust, noise and sewage generated in the production process.
The dust mainly comes from the crushing, screening equipment discharge point, transport transfer point, finished aggregate storage and discharge point, and fugitive dust during loading of the external transportation aggregate, etc.
The noise mainly comes from the operation process of the equipment such as the crusher, the vibrating screen and the like.
The sewage is mainly domestic sewage and contains no harmful substances.
2. Environmental protection measures
1) Dust control measures
A) Dust is produced in the whole process of aggregate production. in order to effectively control dust emission, the dust raising link is reduced as much as possible in the design, the equipment with less dust is selected, and the transportation and feeding equipment with good sealing performance is used. Pay attention to the shape and angle of the material pipe in the design of the material pipe connected by the equipment, and reduce the drop as much as possible.
B) High efficiency dust collector with high dust collection efficiency and reliable technology is used at all dust discharge points. Ensure that the dust emission concentration is lower than 30mg/N, in accordance with the national standard.
C) for the dust removal of finished aggregate storage and unloading point, water spray dust removal can be selected according to the field water source, and the dust emission can also be reduced by building storage and shed in factories in cold areas of northern China.
2) Noise control
Noise control, first, choose the equipment with low noise as far as possible from the equipment selection; second, the equipment with high noise is arranged in the closed factory building.
3) sewage treatment
After pretreatment with septic tank, domestic sewage is used as greening, farmland irrigation and other water, but discharged; spray dust removal water belongs to consumption water, natural evaporation after dust removal.
In view of the large clay content in the raw materials of some mines in the south of China, in addition to the selection principle of the main engine equipment introduced earlier, sometimes the finished aggregate still contains some clay blocks, and the washing aggregate can be considered if necessary.