The fully automatic crystallization, filtration, washing and drying machine meets the increasingly stringent environmental protection requirements for the post-processing production of rare and precious metal powders

Production Status of Rare and Precious Metals such as Gold Salt and Silver Salt
In recent years, with the active precious metal market, the electric key industry has developed rapidly, and the social demand for gold salt and silver salt has continued to increase, which has promoted the prosperity of the gold salt and silver salt industry. Most of the rare and precious metal companies in China used the original production method of manual workshops, and there are many links involved in manual participation. To increase production, the number of workers must be increased, which cannot effectively reduce costs; at the same time, due to the manual operation on site There are many, such as the addition of raw material cyanide, the transfer of products in the process of washing, dissolving, drying, and packaging, etc. Considering that both raw materials and products are highly toxic chemicals, and the product value is relatively high, manual production is easy Accidents and waste of materials occur, thereby increasing production costs, making it difficult to form effective market competitiveness, and restricting the company's further development.



Crystallization drying is an important link in the production of gold salt and silver salt, which directly affects the mass fraction of the product.

The production process previously adopted by Yunnan Tin Copper Industry is to divide crystallization and drying into two independent production steps. The crystallization process is carried out first, and the obtained crystals are transferred to the drying process. However, in the actual production process, many problems have been exposed that have affected the yield and quality of the product, mainly in the following aspects:
(1) There are too many technological processes, which increases the difficulty of control. In gold salt production, the purity of gold salt crystallized at one time cannot reach the mass fraction required by high-quality gold salt. To improve the product quality of gold salt, recrystallization must be carried out.


(2) The production process is to crystallize for the first time in the crystallization equipment, then wash and filter, heat and dissolve, and enter the second crystallization equipment through the pipeline for recrystallization, and the obtained crystals are transferred to the drying equipment for drying. Gold salt products have to be continuously conveyed in different equipment only in the process of crystallization and drying, and the whole process is cumbersome, which increases the difficulty of control. Although the crystallization and drying of silver salt only needs to be crystallized once, it is not advisable to separate these two steps, which reduces the production efficiency.


(3) The conveying process of materials is prone to waste and pollution. In the process of crystallization and drying, especially in the process of crystallization of gold salt, the crystallization is to cool the concentrated liquid with high temperature to obtain crystals, and the process of recrystallization is to heat and dissolve the crystals. There is a very large temperature difference between each equipment, The solution is transported to these devices through pipelines. The solution with high temperature is easy to crystallize in the pipeline, resulting in waste and even blocking the pipeline. Moreover, during the material transfer process, the residual liquid in the container and pipeline will also cause waste and pollution. Gold salt and silver salt products themselves are valuables, and the waste and pollution of materials will bring a lot of losses to the manufacturers.


(4) The maintenance cost of the system is high. According to the original method of Yunnan Tin Copper Co., Ltd. to carry out crystallization and drying, the number of equipment used is large, and the control process is relatively complicated. This will inevitably increase manpower and material resources to ensure the stable operation of the system, thereby increasing the cost of employment. Moreover, for a control system, the failure rate is often related to the complexity of the system. The traditional crystallization drying production process has a low degree of integration and a relatively complicated production process, so the manufacturer has to spend a lot of energy and money to troubleshoot. resulting in lower production efficiency.





Improvement of production process of rare and precious metals such as gold salt and silver salt
Based on the on-the-spot investigation of the production lines of many gold salt and silver salt production enterprises, especially the in-depth investigation and research on the human production workshops of Yunxi Copper and Fujian Zijin Precious Metals Company, an automatic gold salt and silver salt production line was designed , with the purpose of improving the automatic production of gold salt and silver salt, improving production efficiency and product quality, the following work has been done:
(1) Select the production process of gold salt and silver salt with strong implementability and determine the control plan: through on-the-spot inspection and comparison of the production process of many enterprises, and referring to a large number of literature, the advantages and disadvantages of various existing production processes are analyzed, Select an effective process flow; and determine the corresponding control plan in combination with the process flow.
(2) Selection and design of control system hardware: According to the selected production process and combined with the determined production control plan, complete the selection of production process equipment and control modules, design the network structure of the control system and determine its communication mode, according to To ensure production safety, it is necessary to select toxic gas detection equipment and design a monitoring program.
(3) Design of control system software: According to the technical requirements of the production process, the program design and the development of the upper computer configuration software are completed to realize the real-time monitoring of the gold salt and silver salt production process, the automatic control of the production process and the control of the on-site equipment. remote control.


(4) Conduct in-depth research on key processes and propose optimized solutions: According to the needs of actual production, optimize the design of production process control, and verify the feasibility through theory and simulation.

In view of the existing problems in the production of rare and precious metals, Yunxi Copper Industry has adopted the fully automatic crystallization, filtration, washing and drying machine developed and produced by Wuxi ZhangHua Machinery after many investigations, which combines multiple production links of crystallization, filtration, washing and drying together. According to the scheme, the crystallization, filtration, washing and drying links of gold salt and silver salt are all carried out in one equipment, which reduces material transfer links and improves production efficiency.



Structure and working principle of fully automatic crystallization, filtration, washing and drying machine
The all-in-one crystallization and drying machine adopts a barrel-cone structure. Heating jackets are installed on the cylinder body and the lower cone body to heat or cool the material. A hollow shaft and a variable-angle variable-lead hollow screw are installed inside the multi-function machine. The stirring device stirs, stirs and lifts the material, and pushes out the material when discharging.

A conical filtering device with a relatively complex structure is installed in the lower cone, and a specially designed non-dead angle quick-opening discharge device or a non-dead angle pneumatic discharge ball valve is installed at the bottom of the equipment.
The advantage of the fully automatic crystallization, filtration, washing and drying machine is that one machine is multi-purpose, crystallization, filtration, washing and drying are all completed on one machine, reducing intermediate links, and more importantly, the entire process is completed in a closed space, reducing It reduces the interference of the external environment, thereby reducing the pollution of the product by external factors and improving the quality of the product. In addition, the use of crystallization and drying integrated machine reduces the number of equipment, improves the degree of automation, and greatly reduces labor intensity.





Fully automatic crystallization, filtration, washing and drying machine Technical advantages
Many advantages can be found from the actual operation and use of the cylinder-cone filter, washing and drying multi-functional equipment for processing various materials, the main performances are as follows:
(1) One machine is multi-purpose, and can complete various operations such as reaction, extraction, filtration, repeated filtration, washing, and drying in one machine, and the finished product can be obtained directly.
(2) The operating flexibility is large, and the operating cycle can be adjusted by adjusting the filter pressure difference, rotating speed, screw extrusion lead, etc., so as to adapt to changes in process conditions.
(3) The machine can form a very thin filter cake on the surface of the filter medium or filter under the condition of no filter cake. The filtration rate per unit filter area is very high, so the equipment is small and compact.


(4) Fully enclosed system, the operating environment is quite good, especially suitable for handling toxic, flammable and explosive dangerous products, etc.
(5) It can be concentrated and filtered. Especially when it is necessary to wash the material, the material can be concentrated first, and thoroughly washed in the suspension state, and then press-filtered, which can reduce the handling of the material, reduce waste, and do not need to be repulped during washing. The processed product The quality is very high.


(6) It can be used for the three operations of reaction, filtration, and drying, so that the functions of the three unit equipment can be completed on this one equipment, so that the equipment cost, floor area, labor intensity, energy consumption, etc. are greatly reduced.
(7) The power consumption of this machine is low, and the extruded filter cake generally has lower water content than the flat three-in-one machine, and the operation is also convenient.

Domestic rare and precious metal manufacturers have a relatively low degree of automation in the production process. In addition, the raw materials and intermediate products required in the production process are highly toxic, and it is difficult to achieve precise control of the production process.

The fully automatic crystallization, filtration, washing and drying integrated machine developed and produced by Wuxi ZhangHua Machinery Co., Ltd. meets the requirements of fully enclosed production process control and fully automated process of gold salt and silver salt, which is of great significance to improving the quality of gold salt and silver salt products, and also promotes gold salt and silver salt. The vigorous development of the salt and silver salt industry.