Is there a suitable pH meter for determining the endpoint when high-concentration sulfuric acid mixtures are neutralized with liquid alkali?

For your project, using liquid alkali for neutralization in the presence of high concentrations of sulfuric acid and other acids does indeed result in significant heat release, which imposes higher requirements on the choice of pH meter. When selecting a pH meter, it is first necessary to ensure that it can withstand high temperatures and has strong resistance to chemical corrosion. It is recommended to use pH meters specifically designed for harsh environments, such as those with protection ratings and pH electrodes made of corrosion-resistant materials. Such pH meters typically have strong resistance to acids and alkalis as well as high temperatures, enabling more accurate measurements. Additionally, you can also consider using online pH meters, which can continuously monitor changes in the pH value of the solution, allowing for more convenient control of the pH at the end of the neutralization process. If there are concerns regarding the accuracy and stability of pH meters, titration can be considered as an alternative method for determining the neutralization point. Although it may be more cumbersome to use than a pH meter, it can provide highly accurate results. .

In terms of operation, pH test strips are the preferred choice, taking precedence over titration methods; pH electrodes are also a good option.

It would be helpful to know exactly how large the amount of neutralization reaction is and how long it lasts; without quantitative data, it’s difficult to choose the appropriate option.

Under such operating conditions, it is difficult to find a stable and suitable online pH meter, as the probe tends to get clogged. If it must be used, filtration, cooling, and automatic cleaning devices are required, along with automatic switching between multiple probes. It would be more reasonable to provide pH test strips for the position, and use a pH meter for sampling and random inspections. A reminder for the original poster, for reference: 1. The concentration of sulfuric acid you are using is very high; neutralizing it with liquid alkali will result in a vigorous reaction. This imposes high requirements on the corrosion resistance of the tanks, and the working conditions on site will be extremely harsh. It is highly likely that a pre-neutralization tank will be needed to carry out step-by-step neutralization. (We have 20 acids, which need to be neutralized with lime; therefore, a pre-neutralization tank is necessary.) 2. If metal salt impurities are present, hydrogen sulfide may be generated, so an alarm device must be installed on site. Accidents are likely to occur, especially when cleaning sludge from tanks. 3. If the acid content is high at 3.30, waste acid concentration and reuse can be considered depending on the process. It meets environmental requirements and also reduces costs.

For acid-base neutralization titration, the weight or flow rate method is used; finally, a pH test strip is employed for testing, and if that isn’t sufficient, a pH meter is used.