One-Step Brine Purification for Refined Salt

Driven by both the "dual carbon" strategy and the "zero discharge" of industrial wastewater, the traditional salt chemical and salt making industries are undergoing an unprecedented green transformation. Frequent scaling in evaporation crystallization systems? Low mother liquor recovery? Finished salt quality always falling short? Jiuwu Hi-Tech's self-developed PE sintered tubular membrane is injecting hard-core membrane strength into end-of-line salt making processes with its unique material advantages and innovative process route, helping enterprises achieve energy saving, consumption reduction and a leap in quality.

01 Industry Pain Points: The Three Hidden Dilemmas of Conventional Salt Making

At the terminals of well and rock salt, sea salt purification and wastewater resource recovery salt making, conventional processes have three bottlenecks:

Heavy scaling, high energy consumption. Fine suspended solids and residual calcium and magnesium cause severe scaling in MVR evaporators, heat transfer efficiency drops sharply, energy consumption soars, and frequent shutdowns for acid cleaning are required.

Long flow, costly O&M. It relies on bulky settling tanks and sand filters, occupying a large area and consuming large amounts of PAM flocculant; conventional organic membranes age easily and break fibers under high temperature and strong alkali, requiring frequent replacement.

Impurity leakage, thin margins. Impurity interception is incomplete, fine precipitates mix into the mother liquor and are wrapped into salt crystals, reducing the purity and whiteness of the finished product and relegating it to low-value industrial salt.

Under high salinity, high solids and strong alkali conditions, conventional sedimentation and filtration intercept incompletely, while conventional organic membranes age and break fibers easily. Solving equipment scaling and product quality problems requires filter materials that combine corrosion resistance with high precision. To this end, Jiuwu Hi-Tech has provided a highly targeted industrial-grade solution.

02 The Breakthrough Tool: PE Sintered Tubular Membrane

Jiuwu Hi-Tech's PE sintered tubular membrane uses ultra-high molecular weight polyethylene (UHMWPE) sintered at high temperature as a rigid porous substrate, with a modified PVDF separation layer composited on the inner wall. It has four core advantages:

Rigid and pressure resistant

Resists fluid impact and eliminates the risk of fiber breakage and leakage of conventional flexible membranes.

Resistant to acids and alkalis across the full range

Strong chemical inertness, stable over the long term at pH 0-14 and under high-temperature strong alkali cleaning.

High precision and easy regeneration

High interception precision, combined with fluid backwashing, giving a flux recovery rate above 95%.

Wide channel for high solids

Large channel design with an inner diameter of 12 mm or more, tolerating high-solid-content slurries and achieving high concentration factors.

Once membrane material performance was settled, the basis for simplifying existing process flows was in place. Leveraging the strong alkali resistance and high solids tolerance of the PE sintered tubular membrane, Jiuwu Hi-Tech has changed the conventional multi-stage treatment that relies on sedimentation and clarification, embedding membrane separation directly into the front-end impurity removal step and restructuring the salt making process route.

03 Process Breakthrough: Reshaping High-End Salt Making with PE Sintered Tubular Membrane Technology

Jiuwu Hi-Tech has pioneered a short "one-step impurity removal and refining" process: after calcium and magnesium are removed from raw brine by alkali addition, the brine enters the PE sintered tubular membrane system for microfiltration directly, without sedimentation or clarification, and the permeate is sent to MVR evaporation crystallization, with the salt slurry centrifuged and dried to produce finished salt. This process achieves precise breakthroughs:

One: breaking the trade-off between short flow and low O&M

Settling tanks and multi-media filters are eliminated outright, reducing equipment footprint by more than 50%; no PAM flocculant is needed throughout the process; the rigid membrane resists strong alkali and has no fiber breakage, thoroughly solving the problem of frequent filter media replacement.

Two: blocking scaling and stabilizing energy consumption

Outlet SS below 1 mg/L and turbidity below 1 NTU, intercepting 100% of fine crystal seeds outside the membrane and cutting off the cause of evaporator scaling. The MVR maintains efficient heat exchange, energy consumption drops noticeably, and the acid cleaning cycle is extended from "once every few weeks" to "once every few months".

Three: zero impurity penetration and higher quality

Impurities are blocked from seeping into the crystallization mother liquor, the precipitated salt crystals are uniform and pure, and the whiteness and purity of the finished sodium chloride or sodium sulfate are significantly improved, reaching high-end refined industrial salt standards and greatly raising product added value.

04 Industry Outlook: Membrane Technology for the Green Upgrade of the Salt Chemical Industry

From the resource recovery crystallization of high-salinity wastewater to the high-end transformation of bulk salt, the refinement of end-of-line salt making processes has become the inevitable path for the industry. With deep accumulation in high-performance separation membrane materials, Jiuwu Hi-Tech has closely integrated PE sintered membrane technology with salt making processes, helping enterprises achieve the operating goals of "less scaling, low energy consumption, long cycles and high quality".

In the future, Jiuwu Hi-Tech will continue to focus on industry pain points, providing industrial customers with more stable, economical and green integrated separation and purification solutions, and jointly advancing the modern salt chemical industry into a new stage of high-quality development.