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Treatment Of Stone Cutting Wastewater


Release time: 2024-09-23



1. Introduction

At present, the mechanical dewatering method is widely used in the treatment of stone cutting slurry wastewater, and sludge dewatering equipment mostly adopts types with high automation and mechanical pressing force. Firstly, it reduces the manual operation volume, enhances the controllability of sludge dewatering equipment, reduces sludge treatment costs, and secondly, it improves the efficiency of stone wastewater slurry treatment and stabilizes the operation of sludge dewatering equipment through automatic operation.


2. Source and characteristics of stone processing wastewater

The process flow of stone processing is roughly as follows: stone raw materials → sawing machine cutting → grinding machine polishing → cutting and forming → finished products


The pollution of stone wastewater will cause serious water quality pollution, turning originally clean streams into "milk streams" and having a serious impact on the living environment of aquatic organisms. Due to historical reasons, many stone processing enterprises were originally located upstream of the city. The construction of stone processing projects lacked planning and management, and were scattered everywhere. Environmental protection facilities were not complete, and a large amount of production wastewater containing high concentration suspended solids (SS) was discharged into downstream river sections without treatment. This not only wasted a large amount of precious water resources, but also caused serious pollution to the environment, causing concern from all sectors of society. A cutting wastewater treatment equipment


Saw blade cutting wastewater (saw machine wastewater)

The main polluting component of the wastewater from the processing of slate materials is the "coolant" added to the cooling water of stone powder and saw blades. Generally, the main components of the coolant are: resin acids and their saponifiers, Unsaturated fat acids and their saponifiers, lignin and its degradation products, among which resin acids are mainly rosin acids and pimaric acids.


Mill wastewater and trimming machine wastewater

After processing raw materials into boards, the surface of the boards usually needs further polishing treatment. During the polishing process using a polishing machine, there will be a large amount of dust pollutants. To reduce pollution, water is usually used as an auxiliary dust collector. The main components of this type of wastewater are SS and stone powder. During the cutting and polishing process of stone, a large amount of high turbidity wastewater is generated, resulting in waste of water resources and environmental pollution. Especially for small stone processing enterprises, wastewater is directly discharged, causing serious pollution to the surrounding water bodies.


3. Performance analysis of horizontal screw centrifuge

The horizontal screw centrifuge has the characteristics of wide application range, small floor area, large continuous processing capacity, few staff, simple operation, low labor intensity, clean working site environment, good dehydration performance, low total operating cost, and good comprehensive effect. Currently, it is a popular equipment for sewage treatment in domestic enterprises. The horizontal screw centrifuge utilizes the principle of centrifugal sedimentation to separate solid and liquid. Without a filter screen, it will not cause blockage. The continuous operation of the sedimentation equipment has the characteristics of compact structure, continuous operation, stable operation, large production capacity, and convenient maintenance. The machine has good adaptability and corrosion resistance. The components that come into contact with the material, such as the drum and conveyor screw, can all be made of stainless steel to ensure the service life of the machine. The design fully considers the various special requirements of the environmentally friendly sludge treatment process for the centrifuge, and optimizes the design of the main performance components in terms of specificity, adjustability, and other aspects. Before purchasing the machine, users need to explain the physicochemical characteristics and process requirements of the treated sludge in order to provide them with a suitable model.


Separation purpose: solid-phase dehydration, liquid-phase clarification and separation; Liquid liquid solid three-phase separation; Particle size grading.

Different separated materials have different separation characteristics. Even for the same separation material, different process methods and operating conditions have different separation characteristics. The characteristics of the separated materials directly affect the separation effect and processing capacity of the centrifuge.


The settling speed is a crucial indicator for measuring the separation characteristics and plays a decisive role in settling separation. The settling speed mainly depends on the solid particle size, particle shape, Density contrast between solid and liquid, and their viscosity.


The settling speed can be adjusted and improved through the following measures:

1. Adjust the operating temperature to improve the viscosity and increase the Density contrast between liquid and solid phases;

2. Add flocculants to increase the size of solid particles and change the shape of solid particles.