A recycling system for fine sand secondary applications

Abstract

The application provides a recycling treatment system for fine sand secondary application, which comprises a single-layer screening unit, a multi-layer screening unit, a cleaning and dewatering unit and a floatation and desliming unit arranged in sequence along a recycling path; the single-layer screening unit is internally provided with a vibrating screen, a plurality of groups of adjustable vibrators are arranged on the vibrating screen, the installation positions of the vibrators are controlled and adjusted by a control chip, the fine sand is classified according to a particle size-component two-dimensional classification algorithm, and the frequency and amplitude are adjusted according to the classification result; an online particle size analyzer and a mineral component detection probe are arranged at the feeding position of the vibrating screen, the material performs forward or reverse screening movement on the screen surface; and the classification data is introduced into the cleaning and dewatering unit; the multi-layer screening unit is internally provided with a circular vibrating screen, a plurality of circular vibrating screen frame screens are arranged on the circular vibrating screen, and stainless steel screen meshes with different hole diameters are arranged on the circular vibrating screen frame screens.

Description

Technical Field

[0001] This invention belongs to the field of recycling and processing, and specifically relates to a recycling and processing system for the secondary application of fine sand. Background Technology

[0002] In the construction, mining, and industrial manufacturing sectors, fine sand serves as a crucial basic material, widely used in concrete preparation, casting processes, and land reclamation projects. However, waste fine sand generated during production (such as residual sand from concrete mixing, foundry waste sand, and mine tailings) is difficult to reuse directly due to impurities, uneven particle distribution, or chemical contamination. Traditional treatment methods often involve landfilling or simple stockpiling, which not only occupies land resources but can also cause environmental problems such as dust pollution and groundwater infiltration. With the advancement of resource recycling and green production concepts, the secondary application of fine sand has gradually become a focus of industry attention, but existing recycling and treatment technologies still have significant shortcomings.

[0003] Traditional screening equipment is inefficient at processing fine sand, especially when processing fine sand with high moisture content. The screen is prone to clogging, which leads to a decrease in separation accuracy and makes it impossible to effectively distinguish fine sand particles of similar size from impurities (such as clay and organic fragments). The purity of the recovered fine sand is insufficient and cannot meet the requirements of high-value-added applications (such as precision casting or high-grade concrete).

[0004] Existing washing processes mostly employ multi-stage washing tanks or spiral sand washers. While these can remove some surface contaminants, they consume enormous amounts of water, requiring 3-5 cubic meters of water per ton of fine sand. Furthermore, the resulting muddy wastewater is costly to treat, and without an efficient flocculation and sedimentation system, secondary pollution is easily caused. In addition, dewatering processes generally rely on vibrating screens or centrifuges, which are ineffective for extremely fine sand with a particle size less than 0.075mm. The finished product often has a moisture content exceeding 15%, leading to increased transportation costs and easy caking during storage, severely impacting reusability. Some technologies attempt to introduce thermal drying, but this is extremely energy-intensive (requiring 50-80 kWh of electricity per ton of fine sand), making it uneconomical and difficult to scale up. Moreover, for chemically contaminated fine sand (such as phenolic residues in foundry resin sand and heavy metal deposits in mining sand), existing physical sorting technologies cannot effectively remove contaminants, while chemical leaching methods pose a risk of reagent residue, compromising the safety of the treated fine sand and limiting its application in environmentally sensitive areas.

[0005] Existing systems suffer from low automation, with each processing unit (crushing, screening, washing, and dewatering) operating independently. They lack intelligent control and data linkage, making it difficult to dynamically adapt to fluctuations in raw material properties (such as changes in moisture content and impurity types). Manual intervention to adjust parameters is frequently required, leading to unstable processing efficiency and large energy consumption fluctuations. This is particularly pronounced in small-scale, decentralized applications (such as on-site treatment at construction sites), where traditional equipment suffers from large footprint, poor mobility, and low integration, failing to meet the demands for flexible and rapid recycling. These technological bottlenecks severely restrict the promotion of fine sand resource utilization. Summary of the Invention

[0006] This invention proposes a recycling and processing system for the secondary application of fine sand. This system solves the problems of low screening accuracy, rigid parameter adjustment, and serious resource waste in traditional fine sand recycling. Through multi-stage screening and dynamic algorithm synergistic optimization, it achieves accurate classification of fine sand in two dimensions of particle size and composition, real-time adaptation of washing and dewatering parameters, and intelligent control of flotation and desliming process, which significantly improves the secondary utilization rate and recycling quality of fine sand.

[0007] The technical solution of the present invention is implemented as follows: a recycling system for secondary use of fine sand, comprising a single-layer screening unit, a multi-layer screening unit, a washing and dewatering unit, and a flotation desliming unit arranged sequentially along the recycling path;

[0008] The single-layer screening unit has a built-in vibrating screen with multiple adjustable vibrators. The installation position of the vibrators is controlled by a control chip. The fine sand is classified according to a particle size-composition dual-dimensional classification algorithm, and the frequency and amplitude are adjusted according to the classification results. The feed inlet of the vibrating screen is equipped with an online particle size analyzer and a mineral composition detection probe. The material moves forward or backward on the screen surface for screening. The classification data is then imported into the washing and dewatering unit.

[0009] The multi-layer screening unit has a built-in circular vibrating screen with multiple circular vibrating screen frames and screen surfaces. The screen surfaces of the circular vibrating screen frames are equipped with stainless steel screen meshes of different apertures. Each screen surface is equipped with multiple adjustable vibrators. The feed inlet of the circular vibrating screen is equipped with an online particle size analyzer and a mineral composition detection probe. The screen surface has multiple screen holes and screen meshes, and the screen meshes perform forward or reverse screening movements.

[0010] The cleaning and dewatering unit is a vibrating sand washing machine, which is equipped with multiple adjustable vibrators. The installation position of the vibrators is adjusted in real time according to the classification data.

[0011] The flotation desliming unit is a fine sand flotation machine, which contains fine sand and water, and is filled with flotation reagent. The flotation machine is equipped with a dosing device, which automatically controls the dosing module based on the particle size analysis results of the online particle size analyzer, and controls the flotation desliming path based on the results of the online mineral composition analysis probe; the flotation time, flushing intensity and flotation concentration are dynamically adjusted based on the mineral composition and content of the fine sand.

[0012] The innovative design of the single-layer screening unit features a dual-dimensional classification algorithm and dynamic adjustment: While most existing technologies employ single-particle-size screening, this system pioneers a "particle-composition dual-dimensional classification algorithm." This algorithm uses an online particle size analyzer and a mineral composition detection probe to acquire material properties in real time. Combined with a control chip, it dynamically adjusts the vibrator frequency / amplitude (e.g., a frequency range of 50-200Hz and an amplitude gradient of 1-5mm) to achieve directional screening of fine sand with different compositions (e.g., separating quartz sand from clay). Traditional vibrating screens only move in one direction; this system uses a programmable vibrator to achieve alternating forward / backward screening of materials (e.g., switching directions every 5 minutes), effectively solving the problem of screen clogging.

[0013] The multi-layer screening unit incorporates a circular vibrating screen with graded aperture stainless steel mesh (e.g., a three-stage combination of 0.5mm / 1mm / 2mm). Combined with the centrifugal stratification effect of the circular vibrating screen frame, it achieves a particle size classification accuracy of ±0.1mm, far exceeding that of traditional linear screens (±0.3mm). Existing technologies mostly use single-aperture screens, which cannot adapt to complex particle size distributions. Each screen layer is independently equipped with an adjustable vibrator, generating a three-dimensional vibration field through phase difference control (e.g., adjustable from 0° to 180°). Based on the classification data of a single-layer screening unit (e.g., when clay content > 20%), it automatically switches to a high-frequency dewatering mode, dynamically adjusting vibration energy consumption according to the material's moisture content (e.g., reducing the frequency to 60Hz when the moisture content is 15%).

[0014] Compared with existing technologies, this fine sand recycling system offers significant advantages in terms of precision and efficiency in fine sand screening, washing, and flotation. Traditional fine sand recycling systems often rely on a single screening method and a fixed processing flow, resulting in inaccurate fine sand component classification and low recycling efficiency. In traditional systems, the screening process typically uses vibrating screens with fixed frequency and amplitude, which cannot be dynamically adjusted according to different particle sizes and compositions of the fine sand, easily leading to mixing of fine sand components and affecting the effectiveness of subsequent washing and flotation. This system, however, by setting up single-layer and multi-layer screening units, combined with adjustable multiple sets of vibrators, can classify fine sand components according to a particle size-composition dual-dimensional classification algorithm, and adjust the frequency and amplitude of the vibrators in real time to adapt to the characteristics of different fine sands, effectively improving the fine sand recycling precision.

[0015] Specifically, the design of the single-layer screening unit combines a built-in vibrating screen with an online particle size analyzer and mineral composition detection probe, providing real-time data support for the preliminary screening of fine sand. This combination allows for particle size and composition analysis of materials before they enter the vibrating screen, enabling more efficient classification and processing. Traditional technologies often lack such preliminary analysis methods, resulting in less than ideal subsequent processing effects.

[0016] In the multi-layer screening unit, the circular vibrating screen design allows fine sand to undergo multiple screenings. Each screen surface is equipped with stainless steel mesh with different aperture sizes. This design effectively separates fine sand of different particle sizes, thereby improving the purity of the final recovered sand. Simultaneously, the online particle size analyzer and mineral composition detection probe at the feed inlet allow for real-time monitoring and adjustment of the entire screening process, ensuring the stability and accuracy of the screening effect. Compared to existing technologies, traditional systems typically cannot achieve real-time adjustments, resulting in low efficiency in fine sand processing.

[0017] The introduction of a vibrating sand washer in the washing and dewatering unit, combined with adjustable multi-unit vibrators, significantly improves the washing efficiency of fine sand. Traditional washing methods often rely on gravity or simple water rinsing, with limited effectiveness. However, the vibrating sand washer in this system can achieve more thorough washing by adjusting the position and frequency of the vibrators, removing impurities and dirt from the fine sand and improving product purity. This design is relatively rare in existing technology; typical washing units lack dynamic adjustment capabilities, resulting in poor washing effects.

[0018] The design of the fine sand flotation machine used in the flotation desliming unit is also innovative. Traditional flotation machines typically rely on fixed parameters for reagent dosage and flotation time, lacking the ability to dynamically adapt to the composition and content of fine sand minerals. This system, however, utilizes feedback from an online particle size analyzer and mineral composition analysis probe to dynamically adjust flotation time, flushing intensity, and flotation concentration, achieving more precise flotation processing. This dynamic adjustment capability not only improves flotation efficiency but also effectively increases the recovery rate of fine sand, reducing resource waste, and exhibits superior performance, especially when processing complex minerals.

[0019] This recycling and processing system overcomes many shortcomings of traditional fine sand recycling and processing through multi-level screening, dynamic cleaning and intelligent flotation design, demonstrating higher processing efficiency and accuracy, and providing a more efficient and reliable solution for the secondary application of fine sand.

[0020] As a preferred embodiment, it also includes an air separation unit, which is started after the flotation desliming unit. The air separation unit includes a spiral chute and / or an air separator, and adopts two or more sets of spiral chutes connected in series or in parallel. The fine sand is eccentrically moved by the grading roller and the eccentric device to form an inclined forward and reverse curved motion.

[0021] As a preferred embodiment, the particle size-composition dual-dimensional classification algorithm divides fine sand into several particle size intervals, forms a real-time particle size distribution curve based on real-time scanning of the sieve surface, takes the interval containing the maximum particle size on the curve as the target object, takes the part that overlaps with the previous particle size interval as the effective reference object, compares it with the feature value of the current reference object, if it is less than the set allowable error value, it is classified into the next interval, otherwise it is regarded as a non-target object and enters the next cycle, and non-target objects are eliminated through continuous iteration.

[0022] In a preferred embodiment, the real-time particle size distribution curve is obtained by measurement using an online particle size analyzer, and the characteristic values ​​include particle size and composition.

[0023] In a preferred embodiment, after obtaining the characteristic values ​​in the real-time particle size distribution curve, the particle size and composition are analyzed, the analysis results are used to optimize the process, the sorting effect is evaluated by comparing the peak ratio of particle size distribution in adjacent intervals and the percentage of that particle size segment in the entire particle size distribution, and the process parameters are adjusted accordingly.

[0024] The beneficial effects of adopting the above technical solution are as follows: through optimized screening and washing processes, the system can effectively improve the recovery rate of fine sand. The combination of single-layer and multi-layer screening units allows for more precise classification of fine sand during the screening process, reducing component mixing and thus improving the purity of the final recovered product. This improvement not only meets higher market standards but also brings greater economic benefits to users.

[0025] The vibrating sand washer design in the cleaning and dewatering unit significantly enhances the cleaning effect. Through adjustable multiple sets of vibrators, the system removes impurities and dirt from the fine sand during the cleaning process, ensuring the quality of the recycled sand. This efficient cleaning capability reduces resource waste caused by incomplete cleaning and helps improve overall production efficiency.

[0026] The dynamic adjustment capability of the flotation desliming unit enables the system to adapt to changes in different mineral compositions, optimizing the flotation process. By monitoring the mineral composition of the fine sand in real time, the system can automatically adjust the reagent dosage and flotation time, thereby improving flotation efficiency and accuracy. This intelligent processing method allows users to achieve stable recovery results even when dealing with complex minerals, reducing production costs.

[0027] The fully automated design of this system reduces reliance on manual operation and improves overall work efficiency. Through real-time data monitoring and dynamic adjustment, operators can more effectively grasp the production situation, adjust strategies in a timely manner, and reduce errors and fluctuations caused by human factors. This feature enables the system to maintain good working condition in various production environments, improving the reliability and stability of production.

[0028] The system's efficient operation has also brought considerable economic benefits to enterprises. By improving fine sand recovery rates, enhancing product quality, and reducing production costs, enterprises can maintain competitiveness and increase market share. Especially against the backdrop of increasingly scarce resources, optimizing resource recycling and utilization has significant economic and social value.

[0029] This recycling and processing system provides strong technical support for the secondary application of fine sand by improving the recycling efficiency, washing quality, and flotation capacity of fine sand, promoting the sustainable development of related industries, and has significant economic and social value. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a system flowchart of the present invention. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Example:

[0034] like Figure 1As shown, this recycling and processing system is designed and implemented for the recycling of construction waste fine sand. The system consists of a single-layer screening unit, a multi-layer screening unit, a washing and dewatering unit, and a flotation desliming unit, forming a fully automated processing line. The raw material, fine sand, is fed into the single-layer screening unit via a belt conveyor at a feed rate of 3t / h. The vibrating screen is equipped with two sets of adjustable electromagnetic vibrators (0-50Hz adjustable), and the screen surface uses a 5mm aperture stainless steel screen. The online particle size analyzer (laser diffraction type) and XRF mineral composition detection probe at the feed inlet scan the material in real time. When the SiO2 content is detected to be lower than 75%, the control chip automatically increases the vibration frequency to 45Hz and adjusts the amplitude to 5mm, driving the screen surface to form a reverse motion, discharging coarse particles with high impurity content (>5mm) into the waste bin. After the undersize material enters the multi-layer screening unit, the three-stage circular vibrating screen group (screen aperture 2mm / 1mm / 0.6mm) dynamically adjusts the screen surface inclination angle (10°-25°) through a servo motor. When the clay mineral content detected on the second screen surface exceeds 15%, the high-frequency micro-vibration mode (60Hz / 2mm) is activated to effectively separate the muddy fine sand. The 0.6-1mm finished sand after three-stage screening enters the washing and dewatering unit.

[0035] The dual-shaft eccentric block vibrator of the vibrating sand washing machine automatically switches its working mode based on the preceding mineral data: when organic residue is detected, a strong flushing mode (water pressure 0.3MPa) is activated; when carbonate components are present, a weak acid wash (pH=5.5) is used. Finally, the material enters the flotation desliming unit. The fine sand flotation machine automatically adjusts the dosage of sodium dodecyl sulfate (0.8kg / t) based on the D50 value (85μm) fed back by the online particle size analyzer. The ultrasonic generator (28kHz) in the flotation cell dynamically adjusts its intensity according to the clay mineral content, achieving a fine sand recovery rate of over 98%. The system achieves full-process linkage through a PLC controller. Each unit vibrator is equipped with vibration sensors to monitor its operating status in real time. Data is uploaded to the cloud analysis platform via an industrial IoT gateway. When a screen clogging index > 0.8 is detected, the compressed air backflushing system is automatically triggered. The treated fine sand meets the standards for construction sand and can be directly used in C30 concrete preparation. The entire system achieves a water resource recycling rate of 95% and saves 30% energy compared to traditional processes.

[0036] The system also includes an air separation unit, which starts after the flotation desliming unit. This unit comprises spiral chutes and / or air separators, using two or more sets of spiral chutes connected in series or parallel. Fine sand undergoes eccentric motion via grading rollers and an eccentric device, forming an inclined forward and reverse-stopping curved motion. In this technical solution, the air separation unit starts after the flotation desliming unit and includes spiral chutes and / or air separators. This design, when applied in specific working scenarios, can effectively achieve the separation and processing of fine sand. By employing two or more sets of spiral chutes connected in series or parallel, the fine sand, after passing through the grading rollers and eccentric device, forms an inclined forward and reverse-stopping curved motion, which effectively improves the separation efficiency of fine sand. In actual operation, the physical properties and particle size differences of the fine sand are fully utilized to achieve effective separation of fine sand of different particle sizes, maximizing resource recovery and utilization. This air separation technology is particularly suitable for the mining, construction aggregate, and environmental protection industries, improving the quality of fine sand, reducing waste generation, and promoting sustainable development.

[0037] The particle size-composition dual-dimensional classification algorithm divides fine sand into several particle size intervals, forms a real-time particle size distribution curve based on real-time scanning of the sieve surface, takes the interval containing the maximum particle size on the curve as the target object, takes the part that overlaps with the previous particle size interval as the effective reference object, compares it with the feature value of the current reference object, if it is less than the set allowable error value, it is classified into the next interval, otherwise it is regarded as a non-target object and enters the next cycle. Non-target objects are eliminated through continuous iteration.

[0038] In the implementation of the particle size-composition dual-dimensional classification algorithm, fine sand is divided into several particle size intervals, and a particle size distribution curve is generated through real-time scanning. The interval containing the maximum particle size on the curve is used as the target object. This technical solution, when applied in specific work scenarios, enables precise classification of fine sand particles. Through continuous iterative judgment, the algorithm effectively eliminates non-target objects that do not meet the requirements, ensuring that the final selected fine sand meets the set standards in both particle size and composition. This precise classification method can significantly improve product quality and added value, and optimize resource utilization efficiency in fields such as mineral resource sorting, soil remediation, and building materials.

[0039] The real-time particle size distribution curve is obtained by measuring with an online particle size analyzer, and its characteristic values ​​include particle size and composition. This design, applied in specific working scenarios, ensures real-time monitoring of fineness properties, enabling operational decisions during production to be based on scientific data support. In the mining and materials processing industries, real-time particle size and composition data allow operators to adjust processing techniques promptly, ensuring production efficiency and product quality. This real-time monitoring method effectively reduces errors from manual inspection, improves the automation level of the production process, and provides strong support for modern production.

[0040] After obtaining the characteristic values ​​in the real-time particle size distribution curve, the particle size and composition are analyzed, the analysis results are used to optimize the process, the sorting effect is evaluated by comparing the peak ratio of particle size distribution in adjacent intervals and the percentage of that particle size segment in the entire particle size distribution, and the process parameters are adjusted accordingly.

[0041] After acquiring the characteristic values ​​from the real-time particle size distribution curve, the implementation plan of the process is optimized by analyzing the particle size and composition. In specific working scenarios, this design can evaluate the sorting effect by comparing the peak proportions and percentages of particle size distribution in adjacent intervals, thereby achieving effective feedback adjustment of process parameters. This data-driven optimization method can quickly respond to changes in the production process, improving the flexibility and adaptability of the production flow. Especially when facing changes in raw materials or fluctuations in market demand, it can adjust production strategies in a timely manner to maintain product consistency and quality. In industries such as mining, building materials, and environmental protection, this can significantly improve production efficiency and resource utilization, promoting the efficient operation of the entire industrial chain.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A recycling and processing system for the secondary use of fine sand, characterized in that, It includes a single-layer screening unit, a multi-layer screening unit, a washing and dewatering unit, and a flotation and desliming unit arranged sequentially along the recovery path; The single-layer screening unit has a built-in vibrating screen with multiple adjustable vibrators. The installation position of the vibrators is controlled by a control chip. The fine sand is classified according to a particle size-composition dual-dimensional classification algorithm, and the frequency and amplitude are adjusted according to the classification results. The feed inlet of the vibrating screen is equipped with an online particle size analyzer and a mineral composition detection probe. The material moves forward or backward on the screen surface for screening. The classification data is then imported into the washing and dewatering unit. The particle size-composition dual-dimensional classification algorithm divides fine sand into several particle size intervals, forms a real-time particle size distribution curve based on real-time scanning of the sieve surface, takes the interval containing the maximum particle size on the curve as the target object, takes the part that overlaps with the previous particle size interval as the effective reference object, compares it with the feature value of the current reference object, if it is less than the set allowable error value, it is classified into the next interval, otherwise it is regarded as a non-target object and enters the next cycle. Non-target objects are eliminated through continuous iteration. The multi-layer screening unit has a built-in circular vibrating screen with multiple circular vibrating screen frames and screen surfaces. The screen surfaces of the circular vibrating screen frames are equipped with stainless steel screen meshes of different apertures. Each screen surface is equipped with multiple adjustable vibrators. The feed inlet of the circular vibrating screen is equipped with an online particle size analyzer and a mineral composition detection probe. The screen surface has multiple screen holes and screen meshes, and the screen meshes perform forward or reverse screening movements. The cleaning and dewatering unit is a vibrating sand washing machine, which is equipped with multiple adjustable vibrators. The installation position of the vibrators is adjusted in real time according to the classification data. The flotation desliming unit is a fine sand flotation machine, which contains fine sand and water, and is filled with flotation reagent. The flotation machine is equipped with a dosing device, which automatically controls the dosing module based on the particle size analysis results of the online particle size analyzer, and controls the flotation desliming path based on the results of the online mineral composition analysis probe; the flotation time, flushing intensity and flotation concentration are dynamically adjusted based on the mineral composition and content of the fine sand.

2. The recycling and processing system for secondary use of fine sand as described in claim 1, characterized in that: It also includes an air separation unit, which is started after the flotation and desliming unit. The air separation unit includes a spiral chute and / or an air separator, and adopts two or more sets of spiral chutes connected in series or in parallel. The fine sand moves eccentrically through the grading roller and the eccentric device to form an inclined forward and reverse curved motion.

3. The recycling and processing system for secondary use of fine sand as described in claim 1, characterized in that: The real-time particle size distribution curve is obtained by measurement using an online particle size analyzer, and the characteristic values ​​include particle size and composition.

4. The recycling and processing system for secondary use of fine sand as described in claim 3, characterized in that: After obtaining the characteristic values ​​in the real-time particle size distribution curve, the particle size and composition are analyzed, the analysis results are used to optimize the process, the sorting effect is evaluated by comparing the peak ratio of particle size distribution in adjacent intervals and the percentage of that particle size segment in the entire particle size distribution, and the process parameters are adjusted accordingly.

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