Preparation of Wash Solution
The quality and supply of wash solution not only affect the quality of the crushed and washed salt but also impact the consumption of raw salt. Therefore, the preparation of wash solution is of great importance.
When preparing the wash solution, it is necessary to meet the requirements of the washing process. The wash solution must be saturated with sodium chloride and contain as little Ca²⁺, Mg²⁺, SO₄²⁻, and insoluble substances as possible. At the same time, considering the principle of adequate supply, the preparation of wash solution should be tailored to local conditions and be economically viable.
Methods for Preparing Saturated Brine (Washing Solution):
There are mainly three methods for preparing wash solution.
1. Concentrating seawater into saturated brine using salt pans.
2. Dissolving raw salt or fine salt sludge carried away by overflow during production in seawater or brine to produce saturated brine.
3. Dissolving raw salt or fine salt sludge carried away by overflow during production in freshwater to produce saturated brine.
The saturated brine obtained by the above methods needs to undergo sedimentation and clarification to remove the mud and other insoluble substances before it can be used as the wash solution.
Optimized Strategy for Cost and Efficiency:
Among the aboves, Method 1 is the most economical but produces the lowest quality wash solution; Method 3 consumes the most raw salt but produces the highest quality wash solution.
Therefore, to improve washing efficiency and reduce costs, salt washing plants near solar salt pans can combine these two methods, using saturated brine from salt pans as the initial wash solution and higher-quality brine as the final wash solution.