WIRE INDUSTRY ACID PURIFICATION INTERWIRE 2015 DR. ROGER FRANCOIS – BEKAERT TOM PHILIPP, P.E. – PRO-pHx, Inc.

THE CHEMISTRY The catalyst changes the solubility of ferrous chloride and ferrous sulfate into insoluble iron precipitates. Organics are co-precipitated. Acids are purified and not regenerated.

Pickling Tanks

Drag-out Recovery

FILTRATION In the past filtration was done with filter cartridges and filter bags. Previous arrangement was not satisfactory due to its labour intensive nature. Recently, a Two Chamber Global Automatic Back Wash Filtration System was installed. Back washing of the chambers take place when back pressure reaches 1.38 bar (20 psi) or every 1.5 hours. The chambers are air purged before and after back washing to reduce acid loss and dilution. Filter medium is rated at 20 micron.

FILTERS EVALUATED 2008 Global 1X PVC 2009 Westech gravity bag filter 2011 Siebec bag & cartridge filter 2012 Global 2X CPVC

Global 2X CPVC

Automatic Filter Cycles CycleFunction ServiceFiltered acid to pickle tank BlowdownUnfiltered acid to pickle tank FillCylinder fills with water BackpulseAir & water discharge solids BlowdownCylinder emptied of fluid FillCylinder fills with acid

Filter Connections

CHEMISTRY CONSUMPTION ACID USEAGE 6 LITERS/TON CHEMISTRY USEAGE 0.06 LITERS/TON

Project Performance BeforeAfter Bath Concentration g/l HCl16080 Bath DecantsYesNo Iron Concentration g/l100 Max Virgin HCl ReductionNone30% Lime Neutralization ReductionNone70% Filter Cake ReductionNone65%

USA PROJECT ECONOMICS INSTALLED Previous Annual Costs (Virgin acid + Wastewater treatment) $128, Filtration Equipment – Installed 49, Annual chemistry, utilities, labor 32, First Year Savings 47, Future Yearly Savings 96, Period to recover investment 6.8 months

SOUTH AFRICAN PROJECT 25,000 – 35,000 MT/YEAR TWO LINES USED 16% Regenerated Acid – off-site

Off-Site Regeneration Excessive recycle costs – ($ 0.65 /gal) In and out hauling of dilute acids Storage requirements for hazardous waste acid

Drawing of System Layout

Fouled Membrane Reason for having tanks cleaned prior to use of chemistry

African Project Economics Historic annual cost for regenerated acid $ 116,800 Initial cost: equipment installed $ 43,950 Annual operating cost: chemistry/utilities $ 35,830 First year savings $ 37,030 Future yearly savings $ 80,970 Average monthly savings, first 5 years $ 6,015 Period to recover investment 6.5 months

Summary Three wire plants have installed the precipitation chemistry and filtration for continuous acid purification. The technology accomplishes: Lower acid pickling concentrations Elimination of bath decants or dumps Reduced virgin acid purchases Reduced neutralizing chemical purchases Reduced filter cake production Improved process control