Case analysis of typical sandstone aggregate production process

The gravel aggregate production line system generally includes several units: 1 primary crushing unit, 2 semi-finished product storage unit, 3 medium crushing unit, 4 screening unit, 5 finished product storage unit, 6 loading weighing system, 7 water supply and water treatment. Unit, 8 electrical automation systems, 9 spare parts and repair centers.

1 Typical case
Case 1: General Commodity Concrete Aggregate Processing System Process 1
This process (see Figure 1) is suitable for crushing softer and less abrasive rocks such as limestone. It is a typical process of most commercial sand and gravel aggregate processing systems, with simple process and few equipment configurations. The coarse crushing adopts the rod feeder, and the rod feeder has the function of uniform and stable feeding and sieving; the rod sieve is broken into the jaw crusher to improve the production efficiency of the crusher and reduce the wear of the liner. . According to the source condition, the bar sifting material can enter the adjusting material pile together with the coarsely crushed aggregate, or can be removed into the mud sifting machine for mud removal, and the mud removal before coarse crushing can greatly reduce the waste of useful materials. And achieve the purpose of removing mud. Before the crushing, the adjusting material pile is generally set. Due to the discontinuous stability of the automobile transportation, the adjusting material pile can ensure the continuous stable production of the subsequent process in a certain period of time, improve the utilization efficiency of the equipment, and at the same time, when the coarse crushing temporarily repairs or processes the super-diameter stone, the follow-up process is not affected much. The sunstrike impact crusher is used in the medium crushing. The crushed aggregate enters the pre-screening workshop. The aggregates that meet the specifications enter the finished aggregate pile, the super-diameter aggregate enters the fine crushing workshop, and the rest enters the finished screening workshop for screening. The finished aggregate that meets the requirements enters the finished aggregate pile.

This process (see Figure 2) is suitable for crushing harder and more abrasive rocks such as granite and quartzite. Mainly utilizing the principle of “lamination and crushing” of the cone crusher, the finished coarse aggregate is crushed by two-stage cone crusher to obtain a better grain shape. Compared with the scheme 1, in the process of the case 2, the crushing and screening process in the middle section is the same, and the medium and subsequent processes are different. The crushed aggregate enters the pre-screening workshop, and the fine aggregate less than 5mm is sieved out by pre-screening. All the coarse aggregate enters the fine crushing workshop for crushing, and then passes through the finely divided aggregate into the finished screening workshop. The aggregates satisfying the specification enter the finished aggregate pile respectively, and the super-diameter aggregate enters the fine crushing workshop. The fine crushing workshop is provided with the adjustment buffer tank. When the relevant host or other equipment fail and stop, the silo can function as a storage material. The risk of the full cavity and the belt conveyor with load start after the host is stopped is reduced, and the adjustment function of the silo can make the fine crushing cavity full feed, so that the finished aggregate has better grain shape and lower equipment wear. Good aggregate size can reduce the amount of cement, increase the workability, reduce the probability of pumping concrete blocking pipes, reduce the cost of concrete mixing station, and increase the strength of concrete, which is why high-grade concrete has strict control over the grain shape of coarse aggregate. In the process, the finely divided fine aggregate is sieved out without entering the fine crushing. The main reason is that the excessive content of the fine aggregate will fill the gap between the coarse aggregates, reduce the crushing efficiency of the fine crusher, and at the same time, the full feedstock under the circumstances, it is easy to cause the fine crushing equipment to damage. And reduce the service life of the fine crushing equipment. The pre-screening process measures can eliminate this hidden danger.

Case 3: Common commodity aggregates contain sand making system
    The proportion of sand in commercial concrete aggregates is generally about 30%, and the amount is relatively large. Under the current environment of depletion of natural sand resources and limited mining, artificial sand has gradually become a trend and mainstream (currently the main construction of large hydropower stations) It is an artificial mechanism sand). At present, the mechanism sand mainly adopts vertical shaft impact crusher. Because the vertical shaft impact crusher has the functions of shaping and crushing, the sand making process is also relatively more. There are vertical shafts for special sand without coarse aggregate, and some sand making. The process combines the shaping of the coarse aggregate. The process is to make the sand and make the 5~10mm aggregate plastic (and some processes to treat all the coarse aggregates). In this case, the aggregated aggregate and the finely divided aggregate enter the finished 1 screening workshop, and the finished coarse aggregate of 10-20 mm and 20-31.5 mm is sieved, and some of them are 10-20 mm and 20-31. The .5mm finished coarse aggregate and all 5~10mm aggregates entered the sand making adjustment pile. After being crushed and shaped by the vertical shaft impact crusher, it enters the finished product 2 screening workshop for screening. The aggregates larger than 10mm are all returned to the sand making adjustment material pile to form a closed loop, and some of the more than 5~10mm return sand making adjustment piles are formed. Closed loop. In this case, in order to adjust the fineness modulus of the finished sand (the sand is generally adjusted, the medium sand is generally used), and some of the aggregates larger than 3 to 5 mm after the screening are returned to the sand making workshop to form a closed loop.

With the rapid development of sand and gravel aggregates and the expansion of production scale, the design is based on the premise of ensuring product quality, planning according to market conditions, equipment conditions, construction sites, and ensuring environmental sanitation and safe operation. A good system should do the following work: 1 safety (such as site planning; safe space for equipment maintenance operations; lifting equipment above the equipment; site planning and maintenance access; belt profile and walkways and ladders for people on all floors) 2)Environmental protection (using dry process, closed circuit water circulation system and sewage treatment system, sewage to achieve zero discharge; all dust removal points in the plant are equipped with high-efficiency dust removal facilities; on-site road and ground hardening treatment.) 3 High degree of automation (system passed It adopts programming control to realize fully automatic operation. Except special circumstances, no manual interference is required; the system can automatically make fault diagnosis and corresponding treatment, and issue alarm information for the operator to solve.) 5 Energy saving (using low energy-consuming equipment; for production process In the equipment that needs to adjust the medium parameters frequently, the frequency conversion speed regulation is adopted; the substation is as close as possible to the center position of the electric load, etc.) 4 The maintenance is convenient. Special spare parts inventory and repair center