HW Process Technologies

HW Process Technologies' patented Engineered Membrane Separation (EMS^®) is the water filtration of the components of an aqueous stream by applying pressure and flow across a semi-permeable membrane.

• The Permeate, which passes through the membrane and has reduced total dissolved solids (TDS), organic and bacterial contents.
• The Concentrate, which is rejected by the membrane and retains the dissolved solids, organics and bacteria.

EMS^® systems can be designed to selectively remove or pass ions such as:

• Uranium
• Selenium
• Calcium
• Magnesium
• Aluminum
• Gold
• Nickel
• Copper
• Zinc
• Chloride
• Iron

EMS^® systems can be designed to reject silica, organics and colloids as well.

Water filtration produces precise separation at the ionic, molecular and macromolecular levels.  There are three types of membrane separation processes:

• Ultrafiltration (UF) provides filtration in the 0.0015–0.1 micron and the 100,000 molecular weight to colloidal range.
• Nanofiltration (NF) equipment removes particles in the 150–1,000 molecular weight range and rejects selected salts, most organics, and passes more water at lower pressure than RO systems.
• Reverse Osmosis (RO) is capable of the highest filtration level possible, including separating dissolved salts, TDS, and removing bacteria and organics from water.

EMS^® employs spiral-wound membranes using water-specific and application-specific membrane materials of construction and design, as required.

Membrane selection is very important!

Engineered Membrane Systems can match membrane construction and rejection characteristics to site-specific process solution quality and water treatment system requirements.  This will provide the proper recovery and rejection at the lowest operating pressure, achieving the most economical operating costs.

Applications of EMS^® technology continue to expand as the technology is applied to a widening variety of water filtration for aqueous streams for resource recovery and waste minimization.  EMS^® systems have applications where downstream processing economics can be improved by:

• Increased concentration of the valuable components of an aqueous stream
• Removal of suspended/colloidal solids, organic and bacterial matter to reduce adverse downstream effects
• Removal of process contaminants to small 'waste-brine' fractions of a feed stream
• Extraction of process water for re-use
• Reduced neutralization reagent use and associated reductions in the volume of sludge generated, transportated and disposed

EMS^® systems are individually designed to meet site-specific operating conditions.  Membrane engineering will match membrane construction and rejection characteristics to site-specific process solution quality and treatment requirements.

EMS^® systems have been designed and commercially deployed for:

• Mexicana de Cananea
• Kennecott Utah Copper Corporation
• Asarco, Globe Plant
• Cockrell Oil, Utah Gas Field
• Newmont Gold Corporation
• Phelps-Dodge

Application development commences with an assessment of the treatment goals and process solution characteristics.  If treatment via membranes appears viable, a bench-scale feasibility test is carried out on a representative sample of solution (typically, a minimum of 20 liters of sample is required).  The rejection performance of the membrane is determined, and permeate and brine qualities are evaluated.  An order-of-magnitude economic analysis is performed to assess the ability of an EMS^® system to meet process goals.

For projects with a favorable order-of-magnitude economic evaluation, a continous, on-site pilot is typically recommended with a unit capable of processing 40 liters per minute of solution.  The pilot unit is run for a sufficient time to gather definitive design information and to demonstrate to on-site personnel the method of operation of the unit and the proposed process.