SMHDA: Technology facilitates solid Waste treatment, quality showcases expert strength

At present, there is a large demand for sand and other aggregates in domestic infrastructure construction. A large amount of solid waste stone after mine production is piled up, and the efficiency of resource utilization urgently needs to be improved. Processing solid waste stone into machine-made sand for concrete not only solves the problem of land occupation due to stacking but also provides abundant raw materials for the sand and gravel aggregate industry. Meanwhile, the quality of manufactured sand has become an important consideration factor in evaluating the quality of engineering projects, and the production equipment constitutes an important part of the quality evaluation of manufactured sand.

The industry has applied new crushing equipment to handle solid waste and solve the problem of preparing aggregates such as machine-made sand. Meanwhile, many experts and scholars have also put forward new insights into the quality control technology of machine-made sand. As early as the 1980s, developed countries such as those in Europe and America began to successfully use mobile crushing stations to crush some waste reinforced concrete, effectively separating the steel bars from the concrete. Through the processing and treatment of solid waste, it is recycled, maximizing the utilization of resources, reducing environmental pollution and waste.

Guangxi Simanda Construction Machinery Co., Ltd. is a leading professional manufacturer of mobile crushing and screening equipment in China, and has always been dedicated to the research and development and application of technologies in the field of material handling.

Effective measures for improving the quality of manufactured sand and the sand-making process for effectively reducing the mud content have been proposed in the industry. At the same time, the influence of the properties of manufactured sandstone on the performance of cement sand and concrete and other aggregate application technologies have been studied. In response to the characteristics of solid waste stone such as scattered and small volume, and the lack of environmental protection requirements for building fixed crushing equipment, Smanda Company has launched a new type of mobile sand and gravel aggregate production equipment. It features flexible movement, small floor space, and convenient relocation. It can achieve local material acquisition and local production of sand and gravel aggregates, and the quality of its manufactured sand products also meets relevant standards.

Relying on the Guangxi granite project, engineering tests were conducted using the mobile crushing and screening equipment developed by Guangxi Simanda Construction Machinery Co., LTD. The practicality of the equipment was verified, and solutions were proposed for the quality improvement of manufactured sand.

Construction plan design

Mobile crushing and screening equipment mainly includes processes such as crushing, screening and sand making. The main process flow of this equipment includes:

(1) The first crusher uses the S106J crawler-type mobile jaw crusher from Smanda to break down waste rocks smaller than 550mm into stones ranging from 0 to 150mm.

(2) The secondary crushing is carried out using the Smanda crawler-type mobile cone crusher HP300RS to crush the feed and produce small particle size stone materials with a diameter of approximately 0-25mm.

(3) The stone materials enter the S108 crawler mobile screening machine of Smanda and are screened into aggregates with two particle size ranges: 0-4.75mm and 5-25mm.

(4) Stone materials larger than 4.75mm (4.75-25mm) are processed into sand by the Smanda crawler-type mobile sand making machine S315VS. The sand materials of 0-4.75mm screened out by the screening machine and the sand produced by the sand making machine are sent into the sand washing machine to wash away the powder of 0-0.15mm. Finally, medium sand with a particle size of 0.15 to 4.75mm is obtained through a dewatering screen.

Selection of mobile production line configuration

The mobile crushing and screening equipment is equipped with one layer of 4.75mm screen according to the actual needs of the project, while the other layers of screens are not installed. At the same time, a sand washing machine is added to remove particles smaller than 0.15mm, meeting the project's demand for machine-made sand ranging from 0.15 to 4.75mm. According to the characteristics of solid waste stone raw materials, the mobile production line adopts a process design of jaw crusher + cone crusher + screening machine + sand making machine. Granite solid waste stone belongs to the hard rock among hard rocks. It uses waste rock raw materials from surrounding mines. The main parameters of the equipment are shown in the following table:

Spanda Mobile Crushing, Screening and Sand-making Solution Selection Table

The feeding capacity of the above-mentioned equipment is ≥450t/h, which can promote the increase of the production capacity of manufactured sand. Its transportation size occupies a small area and the operation mode is flexible, which can further improve the production efficiency of manufactured sand.

According to the test parameters and the provisions of "Aggregates for High-Performance Concrete" (T/CBMF 38-2018/T/CAATB 001-2018), the fineness of sand is expressed by the fineness modulus and specific particle size. The fineness modulus should be between 2.3 and 3.2, and the specific particle size should be between 4.5 and 7.0. The apparent density and bulk density of manufactured sand shall be no less than 2600kg/m³ and 1480kg/m³ respectively. The maximum crushing value of a single stage of Grade I sand crushing index is ≤20%. Five representative samples of manufactured sand were selected for the test. The gradation (calculated by screening residue), fineness modulus, density, single-stage maximum crushing index, and flaky particle content of this batch of manufactured sand all met the specification requirements, and the overall fluctuation was relatively small. This indicates that the manufactured sand produced by the mobile crushing and screening equipment developed by our company has stable physical properties. This is because the cone crusher can generate a powerful crushing force to fully crush hard granite.

The mobile crushing and screening equipment developed by Guangxi Simanda Construction Machinery Co., Ltd. is highly mobile and flexible, with diverse combinations. It has direct and effective operation effects, can reduce material transportation costs, occupies a small area, and has strong adaptability. It can be customized as needed. The mobile crushing and screening station can precisely achieve the simultaneous preparation of sand and gravel materials, ensuring the quality of machine-made sand. It can also make the entire production process more flexible, guaranteeing that the supply and demand of sand and gravel materials remain in sync.

Based on this Guangxi granite solid waste treatment project, the Smanda team has proposed specific and effective improvement measures for the quality control of the machine-made sand produced in the short line. Smanda has carried out extensive practical and experimental verification work on technical optimization of equipment based on different raw materials to improve product performance. It has jointly promoted the development of mobile crushing and screening technology with experts in the solid waste treatment industry. The future prospects of the solid waste treatment industry are even broader. Smanda uses technology to assist in solid waste treatment and demonstrates the strength of experts with quality.