Achieving High Product Quality in Cobalt Oxide Synthesis - METTLER TOLEDO

Achieving High Product Quality in Cobalt Oxide Synthesis

pH-electrode InPro4800The demand for cobalt oxide is increasing worldwide. For a Chinese producer, accurately measuring pH in their production process was problematic. METTLER TOLEDO’s solution now means high product quality is a certainty, even in harsh conditions of the cobalt oxide synthesis.
 

Increasing demand
Located in Gansu Province, China, Jinchuan Group Limited is a large-scale, non-ferrous metallurgical enterprise. They specialize in the production of nickel and cobalt materials such as cobalt (II,III) oxide (Co3O4), an important raw material in lithium ion batteries, the grade of which can directly affect the quality of the finished batteries.
 
Wet synthesis
The production of Co3O4 comprises two processes: wet synthesis and thermal treatment. The wet synthesis process directly affects the microscopic pattern and chemical composition of Co3O4.
 
Using a water bath, the reactor is kept at a stable temperature and the reactants are fed at a constant rate. A specially designed agitator is used to ensure the evenness of the product, and during the process pH must be maintained at a precise level. As the reaction progresses, cobalt hydroxide precipitates and is converted into Co3O4 through heating.
 
Monitoring system
The control of the cobalt hydroxide synthesis reactor is vital to successful wet synthesis. The temperature inside the reactor, the pH value and the mixing speed are major control parameters. Due to the complexity of the precipitant solutions and given that the precipitation of cobalt hydroxide generated comprises micron level particles that easily adhere to and pollute the electrode, accurate measurement of the pH value is difficult.
 
Unreliable measurements can lead to reduced product quality, so to try and solve the problem Jinchuan Group trialed several solutions from a number of manufacturers. They finally decided that a METTLER TOLEDO system best met their needs.
 
The selected solution comprised the following:
 
Its two electrolyte chambers and PTFE annular junction make it eminently suitable for use in applications where polluting materials and large changes in temperature are present.
 
An extremely stable and reliable unit which features SensoCheck for continuous monitoring of the glass and reference electrodes.
 
The housing chosen is air-powered, retractable and includes a flushing chamber in which the electrode can be cleaned and calibrated.

EasyClean300 cleaning /calibration system:
In combination with the InTrac777 housing the EasyClean300 provides completely automatic electrode cleaning and calibration. Since installation at Jinchuan Group’s facility, the EasyClean300 has been superseded by the even more advanced EasyClean350e.
 
Excellent results
Engineers at Jinchuan Group report that the system runs very stably and reliably, and completely meets the design requirements. The operation of the automatic pH measurement and control system has proven far superior to the previous method, which relied on manual cleaning and calibration. Now, pH control precision during the synthesis process reaches ±0.02pH. This helps Jinchuan Group provide a strong guarantee of high product quality to their many customers, and helps them keep up with ever increasing demand.