Design of fire assay automation control system based on PLC

Abstract This paper proposes an automatic control system for the fire assay laboratory based on PLC, aiming to solve the problems such as time-consuming, labor-intensive, low efficiency, and risks and injuries to staff in high-temperature environments existing in the processes of mixing, discharging, fusion samples, and cupellation of the traditional manual fire assay method. This system is composed of three core modules: the mechanical system, the control system, and the monitoring system. The mechanical system includes the human-machine collaborative operation area, the sample mixing and addition working area, and the crucible and cupel heating area. The control system is composed of both the hardware part and the software part, achieving the interlocking control of equipment and the precise adjustment of process parameters. The monitoring system integrates multi-station environmental monitoring modules and high-precision temperature monitoring modules to collect environmental parameters and temperature change data in real-time. This paper first determines the overall scheme of the fire assay automatic control system, completes the design of the system control mode and mechanical part, then develops the PLC control program and the upper computer software architecture, and finally builds a complete automatic experimental platform. During the testing process, the system achieved significant optimization in terms of time cost, significantly shortened the overall process flow, and the weight of the generated gold and silver alloy particles strictly conformed to the process standards. The test results indicated that the working effect of the system was good.