In view of the difficulties of poor grain shape and high content of small and medium-sized aggregate after basalt processing, the quality of coarse aggregate is mainly controlled by the following measures:
① Measures such as medium fine crushing control crushing ratio, continuous feed gradation, full feeding and laminated crushing are adopted to control the particle shape quality.
② According to the characteristics of the highest content of needle and flake in the small stone after the basalt is crushed by stone crushers, the shaping measures are adopted for the small stone. After medium fine crushing, the first screening workshop produces not only small stone products, but also large and medium stone products.
The aggregate enters the ultra-fine stone crushing workshop, and after shaping, the finished materials of small stone and rice stone are produced in the second screening workshop.
Rod mill and vertical shaft impact crusher are adopted in the system. According to the characteristics of low sand forming rate, high fineness modulus of finished sand and low content of stone powder, following measures should be done.
(1) Increase the rotor speed of the vertical shaft impact crusher and the linear velocity of aggregate in the crushing chamber (65m / s for the system), so as to improve the sand forming rate and the stone powder content of the crushed sand, and reduce the fineness modulus of the sand;
(2) Adjusting the feed grading of vertical impact crusher can improve the sand production effect;
(3) The system has a high content particle size less than 5mm produced after coarse and medium stone crushers. These materials will enter into the vertical shaft impact crusher for shaping, so as to improve the quality of finished sand;
(4) The coarse particles (mainly 3-5mm) after vertical shaft crusher will further enter into rod mill to adjust the fineness modulus and stone powder content of the finished materials;
(5) The lower the moisture content of aggregate is, the better the sand making effect is. According to the characteristics, the whole dry process is adopted to improve the sand making effect of vertical shaft sand making machine. The system not only produces sand for normal concrete, but also sand for roller compacted concrete.