Over a career spanning more than four decades with Eco-Tec and Chemionex, Craig Brown has developed dozens of processes for recovery and purification of a wide variety of metals, salts and other chemicals from aqueous-based waste and process solutions. Following is a partial list. Contact Chemionex for more details on any of these applications. One of these may be similar to your application and could be a spring-board to solving your particular problem. If not, Chemionex would be pleased to work with you to find a custom solution.
1. Development of the Recoflo short bed ion exchange process.
Craig was instrumental in the development of the Recoflo™ short bed ion exchange process, which is currently manufactured by Eco-Tec Inc. Thousands of Recoflo systems have been in installed around the world in dozens of different applications.
2. Development of the APU acid purification unit.
The APU™ acid purification unit developed by Craig has become a world-wide de-facto standard for purification of waste acid in a number of applications. The APU separates strong mineral acids such as sulfuric, hydrochloric or nitric from metallic salts. The unique feature of this process is that only water is required for regeneration of the ion exchange resin.
3. Purification of sulfuric acid anodizing solution
Dissolved aluminum sulfate contaminants buildup in sulfuric acid anodizing solutions. The APU™ acid purification unit, developed by Craig Brown, separates this aluminum sulfate from the acid. The purified sulfuric acid is then recycled back to the anodizing process. This process has become a de-facto standard in the aluminum finishing industry and hundreds of these systems have been installed around the world since its development in the mid 1970’s.
4. Purification of nitric/hydrofluoric acid stainless steel pickle liquor
Dissolved metal salt contaminants build up in stainless steel pickling solutions. The APU™ acid purification unit separates these contaminants from the free nitric and hydrofluoric acid. The purified pickle liquor is then recycled back to the pickling process for reuse. This process has become a de-facto standard in the stainless steel industry and dozens of these systems have been installed in mills around the world.
5. Recovery of low levels of lithium from concentrated brine
The demand for lithium for use in lithium ion batteries has grown exponentially with the advent of electric vehicles. Chemionex has developed a unique ion exchange process for recovery of low levels of lithium from concentrated brines. The process is currently in the demonstration phase and should reach commercialization in 2020.
6. Removal of chloride contamination from concentrated sodium sulfate solution in the pulp and paper industry
A unique ion exchange process was developed and commercialized for kraft pulp mills for removal of chloride contamination from sodium sulfate recovered from the recovery boiler. The unique feature of this process is that only water is required to elute the chloride from the ion exchange resin. The process has been successfully commercialized in a number of kraft mills.
7. Purification of nitric acid plating-rack strip solution
Dissolved nickel and copper contaminants build up in nitric acid used to strip electroplating racks. The APU acid purification unit separates these contaminants from the free acid. The purified nitric acid is then recycled back to the stripping process for reuse. The process has been successfully installed in many plating operations since its development in the 1970’s.
8. Recovery of nickel salts from electroplating rinsewaters
Cation exchange is used to recover nickel from nickel electroplating rinsewaters. The nickel is recovered as a concentrated nickel sulfate / chloride salt by acid regeneration of the cation exchanger. An APU™ was integrated with the cation exchanger to recover the excess acid use for regeneration, so that the recovered nickel salt is at pH ~4. Dozens of these systems have been installed over the past thirty years.
9. Recovery of chromic acid from electroplating rinsewaters
A concentrated chromic acid solution is recovered from dilute chromium electroplating rinsewaters. Over one hundred of these systems have been installed over the past thirty years.
10. Purification of hard chrome plating baths
Cation exchange is used to remove contaminants such as iron and trivalent chromium directly from hard chromium plating baths. Dozens of these systems have been installed over the past thirty years.
11. Recovery of phosphoric acid from aluminium bright dip rinsewaters
Aluminum is removed from aluminium bright dip rinsewaters by cation exchange. The purified dilute phosphoric acid is then concentrated by evaporation for reuse in the bright dip process. This has become a standard in the aluminum finishing industry.
12. Softening of high TDS oil field produced water
Normally, weak acid cation exchangers are employed to soften high TDS brackish water such as oil-field produced water. These WAC resins require regeneration with hydrochloric and sodium hydroxide. A novel ion exchange process that uses only salt for regeneration was developed and commercialized.
13. Removal of sulfate contamination from concentrated sodium chloride brine
Sulfate contamination builds up in concentrated chlor-alkali brines. An ion exchange process was developed to remove the sulfate. A unique feature of the process is that the ion exchange resin is regenerated with only water. No chemicals are required.
14. Removal of trace fluoride contaminants from concentrated sodium chloride brine
Sometimes reclaimed brine is used in chlor-alkali plants. In this case, fluoride contamination may be an issue. An ion exchange process was developed to remove the fluoride. A unique feature of the process is that the ion exchange resin is regenerated with only water. No chemicals are required.
15. Softening of concentrated sodium chloride brine
An ion exchange process was developed to soften concentrated sodium chloride brines. A unique feature of the process is that the ion exchange resin is regenerated with only water. No chemicals are required.
16. Removal of heat stable salts from amine gas scrubbing solutions
Heat stable salts such as sulfate and thiocyanate accumulate in amine solutions used to scrub sulfur from petrochemical gases. These salts are not removed in the steam amine regeneration process. The ion exchange process that was developed to remove these heat stable salts is fast becoming a world-wide standard in refineries.
17. Removal of trace copper from hydrochloric acid steel pickle liquor
Trace levels of copper can build up in hydrochloric acid steel pickle liquors, even when a roaster is used to regenerate the pickle liquor. An ion exchange process was developed to remove the copper from the HCl, even in the presence of high iron concentrations. The copper is stripped from the IX resin with only water. The process was piloted and successfully commercialized.
18. Removal of iron zinc from hydrochloric acid steel pickle liquor
Iron and zinc contaminants build up in hydrochloric acid used to pickle steel prior to galvanizing. An ion exchange process was developed to remove the iron and zinc from the HCl. The zinc and iron are stripped from the IX resin with only water.
19. Removal of maleic acid impurities from malic acid
An anion exchange process was developed for the food industry to remove maleic acid impurities from concentrated malic acid solution. This process is much cheaper than the conventional crystallization process. The process was piloted and has been successfully commercialized.
20. Removal of divalent metal impurities from concentrated lithium salt solution
Battery grade lithium must be very pure. An ion exchange process was developed, piloted and commercialized to remove calcium and magnesium from lithium chloride solutions used to produce lithium carbonate.
21. Recovery of iodine from oil field produced water
A novel ion exchange process was evaluated to recover iodine from oil-field produced water.
22. Recovery of gallium from sodium aluminate / sodium hydroxide Bayer liquor
Solvent impregnated resins are used to recover gallium from sodium aluminate / sodium hydroxide Bayer liquor. The process was optimized and improved procedures for impregnating the resins were developed.
23. Separation of gallium, indium and tin in hydrochloric acid
An ion exchange process was developed to recover and separate gallium, indium and tin in hydrochloric acid. Only water is employed to strip the metals from the ion exchange resin. The process has been successfully commercialized.
24. Removal of cadmium and lead from battery recycling wastewater
Chelating ion exchange resin was used to reduce the levels of cadmium and lead in the plant effluent from a lead-acid battery recycling operation. The process has been successfully commercialized.
25. Removal of organic contamination from concentrated metal salt solution
Based upon the client’s preliminary bench-scale tests, a fully automated pilot plant was designed and constructed from removal of organic contamination from a concentrated metal salt solution.
26. Recovery of rhenium from super alloy scrap
Rhenium is reclaimed by leaching super alloy scrap in concentrated acid. Based upon the client’s preliminary bench-scale tests, a fully automated pilot plant was designed, constructed and tested to recover rhenium from the leachates. Chemionex did the process design for the full-scale industrial plant based upon the pilot plant data. This system was constructed and is operating successfully.
27. Removal of cadmium from solar panel recycling wastewater
Hydrochloric acid is used to strip cadmium and other metals from scrap solar panels. After the metals have been stripped from the glass, the glass is rinsed with water. The rinsewater is contaminated with cadmium and must be discarded. An ion exchange process employing chelating resin was developed and commercialized to remove these toxic metals from the effluent.