Concentrated brines and bitterns rejected from various processes contain mineral salts of economic value. For example, sulphate-rich bittern generated at saltworks in the Rajasthan state of India exceeds 3 million tons annually and requires adequate treatment. Resource recovery from such unutilized by-products presents a sustainable waste management approach. This work presents the development and evaluation of a process for sodium-sulphate (Na₂SO₄) recovery from sulphate-rich bitterns using an integrated process combining cooling crystallization, filtration, and drying as major unit operations. A parametric study has been conducted to investigate the effect of various operating parameters on product (anhydrous sodium-sulphate) yield and quality. Chemical analysis, TGA, P-XRD, and SEM-EDX techniques were used to characterize the product quality and purity. Based on the parametric studies, a sodium-sulphate production process was designed, and material & energy balance was established. The mass balance calculations have shown that 1 ton of anhydrous Na₂SO₄ (~97 wt% purity) can be produced from 6.31 tons of bittern having a sulphate ion concentration of about 140.8±6.94 g/l. Subsequently, the economic feasibility of a 5 ton/day anhydrous Na₂SO₄ capacity plant has been evaluated using the cost and profitability analysis. The engineering-economic calculations suggest that the sodium-sulphate production from bittern can be economically favourable, achieving a payback period of 3.5 years. The optimized parameters and economics presented in this paper could significantly help implement an actual sodium-sulphate recovery unit using sulphate-rich bittern as feed.

从各种工艺中剔除的浓盐水和卤水都含有具有经济价值的矿物盐。例如，印度拉贾斯坦邦盐厂产生的富含硫酸盐的卤水每年超过300万吨，需要进行适当的处​​理。从这种未利用的副产品中回收资源提供了一种可持续的废物管理方法。这项工作介绍了硫酸钠（Na ₂ SO ₄）采用整合了冷却结晶，过滤和干燥等主要操作的集成工艺，从富含硫酸盐的卤水中进行回收。已经进行了参数研究，以研究各种操作参数对产品（无水硫酸钠）产量和质量的影响。使用化学分析，TGA，P-XRD和SEM-EDX技术来表征产品的质量和纯度。在参数研究的基础上，设计了硫酸钠的生产工艺，并建立了材料和能量的平衡。质量平衡计算表明，可以从6.31吨具有约140.8±6.94的硫酸根离子浓度的卤水中生产出1吨无水Na ₂ SO ₄（ 纯度约为97 wt％） 克/升 随后，使用成本和获利能力分析评估了一座5吨/天的无水Na ₂ SO ₄装置的经济可行性。工程经济计算表明，卤水生产的硫酸钠在经济上是有利的，回收期为3.5年。本文中提出的优化参数和经济性可以极大地帮助实施以富含硫酸盐的卤水为原料的实际硫酸钠回收装置。