Regarding the TOC control criteria for crude salt
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I would like to ask my colleagues whether there are any controls in place regarding the TOC level of the raw salt used, and if so, what are the specified limits?
I’m not entirely sure about this, but in the end it comes down to the TOC level of the brine. Moreover, different companies use different processes; for example, we don’t add sodium hypochlorite to the primary brine. Furthermore, TOC does not necessarily originate from the raw salt; it may also come from materials added from various sources. I remember once the TOC level of our brine was high; upon investigation, it turned out to be coming from the sodium carbonate solution.
The national standards for raw salt do not include an organic matter parameter; I guess few chlor-alkali companies have conducted analyses of the TOC level in raw salt. Companies may have specific requirements regarding their raw materials, and currently there is an oversupply of the market, with plenty of high-quality raw salt available.
Several chlor-alkali companies in our industry have begun to pay attention to the TOC value of raw salt. Currently, high TOC levels often lead to a sudden increase in cell voltage; however, it’s not clear whether there are other factors that also have an impact. Therefore, we would like to ask if, in addition to the commonly tested parameters such as sodium chloride content, calcium and magnesium ions, sulfate ions, and insoluble substances, other indicators are also checked when testing raw salt
Metals present in the secondary brine, such as nickel, silicon, iron, aluminum, lead, etc., can be analyzed if conditions permit; iodine as well. Any element for which there is data indicating it can cause an increase in cell voltage can be investigated and analyzed. This can extend the lifespan of the ion membrane.
The analysis results from our company are generally below 10; according to the latest research, organic substances have a certain impact on the anodic coating
For the anode coating? Are there any relevant materials?