Mainland new large stone crushing stone English sandstone resolve the situation

Problems and influencing factors in July 2008 started running, after system commissioning, in addition to other varieties of large stone outside the coarse aggregate quality

requirements are met. Large number of stone to meet the premise of flakiness content and maximum edge length does not meet the requirements; satisfy the premise of quality

Can not meet the production requirements, while controlling the content even flakiness specifications will still be within the scope of the phenomenon of long strips. Analysis

of the reasons, the main factors affecting the performance in the following aspects.

(A) the source material properties. After metamorphic quartz sandstone, the crystal orientation, anisotropy is generated during processing and flakiness elongated main reason.

(2) equipment limitations. Finished material transport with a diameter of 500mm continuous belt conveyor tube bend, allowing the transport of materials maximum particle size of

150mm, combined with expert advice, large stone limit the maximum edge length does not exceed 250mm. Also, according to "Hydraulic Concrete Aggregates testing procedures"

Requirements, does not allow a large stone produces flakiness.

(3) Concrete gradation adjustment. 2009 design units and field trials to determine the center of the concrete dam concrete test report with a ratio of four large stone: stone:

the stone: stone = 35:25:20:20. Large proportion of original stone set 30:30:20: 20 percentage basis

There is a certain amount of increase.

Process Improvement test for the problems, the project implementation process for a number of improvements trials, including crushing nesting population adjustment, mesh

screening machine and structural adjustment, broken cone machine nesting population adjustment, intermediate impact crushing equipment and primary impact crusher, etc. Improved test, trial

The main purpose is to solve test large stone in the number of simultaneously satisfy the feed Jinping Hydropower Station to meet the quality requirements.

Primary Impact Crusher combo test. Impact crusher crushing the use of two test speed is 90% greater than 80mm diameter, respectively, of semi-finished material in the crusher

speed 32.5m / s and 42m / s when the test results. It can be seen from, the line speed change, particularly

Boulder yield is not obvious, 44m / s transfer speed is better, the actual content of semi-finished products in the proportion of more than 80mm should be around 50%, large

stone actually get about 20%.

Primary Impact Crusher complete crushing plant wool also carried out tests, test results and crushing cycle comparison, the test results is the use of primary counterattack crusher wool less

effective, large stone to get rate has dropped by about 5%, the maximum edge length up to 500mm .

Finished material quality testing system table entries particle content of a percentage /% 80 ~ 15040 ~ 8020 ~ 405 ~ 20 <5 Gradation 22.420.022.919.415.3 flakiness

9.211.712.68.5-state current King Stone needle chip content controlled at 10%, but with side length 250mm

The proportion reached 40%, the maximum edge length is still exceeded 350mm, the production ratio can reach 25% or more, basically meet the dam material. Due to multiple shaping

the stone proportions and significantly higher proportion of disposable materials. Through concrete test, large stone strips on concrete performance has little effect, but the

tube

Difficult to transport with a machine. To ensure the smooth construction of the concrete dam, dam concrete system settings in the car by the material pit, large stone used car

transport. Adjust stirring downstairs spout, maintaining four with concrete production.

Conclusion Yin Bazi ditch aggregate processing system, since the operation, production and testing has been implemented to explore solutions to cross large stone quality and

yield of the ultimate goal. It should be said that the current combination of technology and equipment configuration tends to the ideal state, but there are still large stone

production targets

Elongated ones, the problem of insufficient production proved lithology processing performance is causing the biggest reason for this series of questions, indicating Jinping

metasandstone processing four with the production process so far has not been a corresponding countermeasures, aggregate processing system is still worthy of further overcome

Issues, it also brings to similar projects explore and think: ① equipment and equipment level there is currently expanding space, such as those for special elongated aggregate

crushing parameter design, both to avoid excessive fragmentation, can be measured reliably shaping to ensure quality ; ② expansion of existing space craft link exists

In the current session on the basis of the existing process, it may explore a special new technology; ③ focus on follow-up system device configurations, such as transportation

systems and concrete finished device configuration and system processing performance matching and lithology combination, can be ordinary tape machines and self-loading mixed

Concrete mixing plant; ④ dam mix design to fully consider the source material processing properties, such as the use of three with four alternative distribution and so on.