About the Technology

The technology uses innovative membrane tubes patented by Pervatech Corporation in the Netherlands. The tubes were originally designed to separate heavy oils, paraffins, and alcohols in Europe. Our company acquired these tubes and repurposed them in the US by redesigning a pilot plant with completely different configuration from the traditional units. The goal was to process underground brine water, industrial effluents, dilute leach solutions and separate mineral salts from freshwater. We own the utility patents for the process itself, module assembly and demo plant design.

MEMBRANE TUBES

The narrow tubes are made from robust and sturdy silicate material ranging in diameters between 10-15 mm (about 0.59 in), and length of up to 1.2 m. The selective properties of the membrane tubes are imparted by a thin coating of porous polymer-silicates on the exterior diameter. Given their fragility (they can break on strong mechanical impact), they are housed in cylindrical metal casing called modules. In each module, there could be as many as 148 tubes tightly secured. The module itself, which houses membrane tubes, is made from stainless steel 304 or SS316. The material can handle wastewater at pH 0.2 or higher with dissolved silica up to 2500 ppm. The cylindrical housing can operate under different pressure conditions. 

THE PROCESS

The feedstock solution enters at one end of the tube and exits at another. The exit mineral salt solution, under near ambient pressure, becomes concentrated after water molecules are selectively removed. 

Water molecules, with smaller diameters, will diffuse through the porous silicate and eventually permeate through the selective coating before exiting outside the tube (Permeate). The larger molecules of soluble salts (silicates, sulfates, sulfides, chlorides, carbonates, fluorides, urea compounds) remain behind and exit the tube at higher concentrations than before (Retentate).

In summary, we should state that the process achieves the following results:

• rejection of 99.99%wt. mineral salts containing traces of hydrocarbons and dissolved silica.
• produces 80-86% wt. of freshwater 
• produces a concentrated solution of metal salts (14-20%wt)
• mineral salts may crystallize out of the mineral-rich solution at low temperature. The following mineral salts are recovered from the mineral-rich concentrate solution using a proprietary technology: LiCl, REE-Chlorides, CuCl2, FeCl2 and MgCl2.

BENEFICIATION OF CONCENTRATES

The membrane technology generates a small volume of concentrated solution rich in mineral salts (14-20%wt) such as MgCl, LiCl and Rare Earths. The upside to this technology is that these mineral salts can be recovered and sold to pay for the operations of the freshwater recovery plant.

In geothermal power plants, the solution exiting the turbines is rich in mineral salts. Traditionally, mineral-rich concentrates are injected back into wells. This technology can process hot geothermal brines (90-100℃) at a pH 6 -7, containing high dissolved silica (1000-2500 ppm), sodium (40-200 g (about 7.05 oz/L), lithium (60-100 ppm), magnesium (120 –1550 ppm) and iron (1000-3000 ppm). Lithium is recovered at higher temperature (>90℃) to avoid premature precipitation of unwanted metal salts.

In 2017, our company demonstrated the ability to concentrate and recover Lithium in brines from Arizona’ s lithium underground sources (Clayton Valley). The area can generate 10,000 gpm of brine containing Li (60-110 ppm) and Mg (500-3000 ppm) and 450-600 ppm, dissolved silica. Mineral salts were upgraded by a factor of 8-12.