A FINAL YEAR PROJECT IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR A BSc. HONOURS DEGREE IN MECHANICAL ENGINEERING.
A dosing system is a device or system that is used to add a precise amount of substance, to a process or product. Dosing systems which rely on manual Dosing have several problems in various applications. These can be inaccurate Dosing, inconsistent dosing, operator error, safety concerns, monitoring and control. This project is to show the design of an Automated Lime Dosing system for Bulawayo Mining company (HOWMINE) using an Arduino microcontroller. The software called Arduino IDE is utilized to create a program that enables a microcontroller to establish communication with various sensors and hardware components. The circuit consists of several devices including a pH sensor an ultrasonic sensor, a servo, a liquid crystal display, and a DC pump. In case the pH level goes beyond a specific range, the DC pump is activated automatically to restore the pH value of the pulp to 9. The LCD shows pH values and water level. The role of lime is to act as a pH control agent for optimal cyanidation leaching of gold as well as being a neutralisation agent. Lime when exposed to people can aggravate disorder to the eyes, skin, gastro internal tract and respiratory system. Prolonged exposure leads to persistent coughing and breathing problems which can lead to chronic lung disorder, silicosis, etc. Current Dosing system is whereby operators add lime from 25kg bags onto a moving conveyor belt that is exposed to air. Hourly additions require employees working in close proximity to evacuate the dosing site leading to an increase in downtime. This project ensures that there is no exposure of operators to lime, the system is automated minimizing operator handling and making it environmentally friendly as the lime is to be dosed in solution form.