The pursuit of greener and more efficient industrial processes is a constant endeavor in the chemical sector. In the realm of electrolytic manganese (Mn) and electrolytic manganese dioxide (EMD) production, the use of selenium-based additives, while beneficial for process efficiency, has raised environmental and health concerns. This is where innovative additive combinations, such as the synergistic pairing of selenious acid (H2SeO3) and sodium sulfite (Na2SO3), become critically important. NINGBO INNO PHARMCHEM CO.,LTD. is actively engaged in exploring and promoting such advancements.

Historically, selenious acid has been a standard additive in electrolytic manganese production. It plays a vital role in improving the deposition of manganese metal by enhancing cathodic polarization, which, in turn, suppresses the undesirable hydrogen evolution reaction (HER). This leads to higher current efficiencies and better quality manganese deposits. However, the inherent toxicity of selenium and the potential for its accumulation in the final product necessitate a reduction in its usage. The challenge lies in achieving these process improvements without compromising efficiency or product quality.

Recent scientific investigations have shed light on the efficacy of using sodium sulfite as a co-additive with minimal amounts of selenious acid. This approach has demonstrated remarkable success in not only maintaining but often improving upon the performance metrics achieved with higher selenium concentrations. By carefully balancing the ratio of H2SeO3 to Na2SO3, producers can significantly decrease the overall selenium input while simultaneously enhancing key process parameters. A concentration of 0.0175 g/L for H2SeO3 coupled with 1.5 g/L for Na2SO3 has been identified as an optimal combination.

The advantages of this composite additive system are substantial. Firstly, it leads to a significant improvement in current efficiency for both cathode (manganese metal) and anode (EMD) deposition. This translates directly into higher productivity and reduced operational costs. Secondly, the quality of the deposited manganese is notably enhanced, characterized by a smooth surface, metallic luster, and uniform thickness, with the desired α-crystal morphology. The electrolytic manganese dioxide also benefits from this optimization, exhibiting uniform particle size and the correct crystal structure. Most importantly, this strategy allows for a substantial reduction in the reliance on selenious acid, offering a more environmentally sound production method. This aligns perfectly with the sustainability goals championed by NINGBO INNO PHARMCHEM CO.,LTD.

The electrochemical analysis underpinning these findings further validates the benefits. The presence of both additives shifts the manganese deposition potential favorably, indicating more efficient manganese ion reduction. This also means that less energy is required for the electrolytic process, contributing to both economic and environmental benefits. The suppression of HER by Na2SO3 is a key factor enabling the reduction in H2SeO3 concentration without sacrificing performance.

In conclusion, the strategic application of composite additives, particularly the combination of sodium sulfite and selenious acid, represents a pivotal advancement in electrolytic manganese and EMD production. NINGBO INNO PHARMCHEM CO.,LTD. advocates for and supports the adoption of such innovative solutions that balance efficiency, quality, and environmental responsibility, paving the way for a more sustainable future in metal processing.