Air Pollution Control Innovations

Three Things to Do Before a Stack Compliance Test

Posted by Andy Olds on Mon, Nov 02, 2015 @ 08:00 AM

Compliance testing often brings anxiety to environmental managers.  Testing is expensive and can comprise a significant fraction of the environmental operating budget.  Planning takes several months, often culminating in a tight testing window with long days and unforeseen delays.  And always looming is a dreaded phone call of a failed test.  What three things should environmental managers do to ensure a successful compliance test?


  1. Calibrate your control instruments

Manufacturers use complex instruments to ensure that their equipment meets its performance objectives.  These instruments must remain calibrated for the control equipment to perform properly. pH sensors, ORP probes, flow transmitters and conductivity sensors ensure optimal acid gas removal.  RTDs and thermocouples are vital to reliable operation for thermal oxidizers, condensers and reheaters.  Pressure transmitters provide important information for the performance of Venturis, and the condition of baghouse, carbon beds and packed beds.

The most common deficiency reported in our service call database is an out-of-calibration instrument.  Make sure that your instruments calibration is up to date, and check its performance a month prior to compliance testing to ensure you have the time to order a replacement instrument if required.

  1. Inspect and clean your equipment

Environmental control equipment typically faces an array of upset conditions.  Waste streams change or cycle through daily, weekly or seasonal disruptions.  Auxiliary equipment fails leading to changes in the quality of makeup water, instrument air, or power.  Repeated startups and shutdowns lead to transient states of substandard performance.  The struggle to keep environmental compliance equipment operational at all times leads to an "emergency-only" attitude towards preventive maintenance.  All of these factors lead to degradation of equipment and instruments.

Ahead of compliance testing, it is important to challenge the operations staff to inspect and clean the equipment.  Ensure instruments do not have buildup that dampens response time.  Confirm pressure drops across filters, strainers, spray nozzles are at design conditions; high pressures may be indicative of fouling.  Make sure consumables such as pH probes and filter bags are new and up to date.  Check for air ingress; most compliance tests measure the oxygen content of the gas to ensure that emissions are not artificially lowered by dilution air.  Clean sumps, separators and nozzles during regular shutdowns.  Ensure that your emissions are limited to that which occurs during steady state operation, and not from old emissions that have built up on the internal surfaces of your equipment.

  1. Interview your stack tester

The EPA has well-developed procedures for every type of emission test.  However, with ever lowering standards, stack testers are forced to push their instruments and apparatuses to their technological limit in order to accurately measure emissions.  Stack testers have found ways to extend these limits, but the difference between emissions and noise is narrowing.  Minimizing the noise, and understanding the methodology of the stack test, will ensure you and your equipment are well-prepared.

For all stack tests, ask the following:

  • What EPA procedures will you be using?
  • Are there any known interferences for the procedures?
  • What is the experience level of the stack test operators with each procedure?
  • Are you prepared for lower than expected gas flow rates, greater than expected dilution, or other flue gas variances?

For initial testing:

  • What is your expectation of the non-detectable limit with the procedure provided?
  • Is the expected non-detectable limit sufficiently low to provide accuracy below my emission limit?
  • How do you intend to reliably rig and stabilize your instruments?
  • What can I do to give the stack testers the best opportunity to provide reliable data?

If your permit has changed since your last stack compliance test:

  • Have you accounted for my new permit requirements, and how has that changed your testing protocol?

Getting ready to perform a stack compliance test?  Contact Envitech Service for a site visit to calibrate your instruments and inspect your equipment.

Contact Envitech Service

Topics: Stack Testing

Three Key Tools Envitech Uses To Improve Scrubber Service

Posted by Andy Olds on Mon, Oct 26, 2015 @ 08:00 AM

Envitech recently launched a new Service Program to provide scrubber operators with a knowledgeable and responsive resource to keep their air pollution control equipment functioning properly.  One of the service program options is true 24-7 remote plant coverage that connects operators directly with our service staff.  To be able to offer this service as a small business requires both dedication from our service team and implementation of the latest service technology.  In this post, we discuss the technologies we rely upon to offer this service. 


In the last year, Envitech has stepped up its use of FaceTime to remotely communicate with service technicians.  For those unfamiliar with the technology, FaceTime is an Apple application that connects users by video through their mobile phone.  Below are screen shots of a FaceTime connection using WiFi.

Envitech has found that the quality of this technology has improved such that engineers can remotely direct technicians through troubleshooting, calibration, or simple repairs.

For scrubber operators equipped with an Apple product, FaceTime provides an immediate and direct method to connect to our service technicians.  FaceTime's realtime video technology lets Envitech technicians see the issue, direct the repair, and confirm a successful outcome, all without the cost and downtime of a site visit.


Envitech has invested heavily in PLC and HMI training for its engineers.  All of our engineers are capable of minor modifications of PLC logic, online changes to HMI screens, and trending data through PLC software.  Until recently, this level of assistance was not available remotely.  Older peer to peer technologies were not sufficiently reliable to allow logic interface.  HMI screens were typically built remotely and uploaded onsite by a qualified operator.  Trending was often not available "live" and had to be downloaded and transmitted by a trained software specialist.

Envitech purchased GoToAssist in 2014 to connect our engineers to our startup teams.  GoToAssist is a Citrix product that connects the user to a remote computer by invitation.  Upon acceptance of a connection, the remote engineer can manipulate the local computer.  Below is a photo of the GoToAssist software from the engineer's perspective.

Envitech has found the software to be tremendously useful, reducing our startup team sizes, shaving days off the startup schedule, and increasing the accessibility of our variety of engineering talent.  Customers have caught on, seeing how quickly and effectively we can make programming changes remotely to improve their process, and have requested this as an add-on service.  To date, we have logged over 125 support session with customers totaling more than 400 hours of remote troubleshooting using GoToAssist.

Some of the tasks our customers have enjoyed using remote troubleshooting via GoToAssist include:

  • Rescaling ranges within the logic for replacement instruments
  • Trending process and control variables to tune control loops
  • Revising HMI screens live with operator feedback
  • Downloading operational data for analysis
  • Adjusting stoking frequencies for incinerators and cleaning frequencies for WESPs

Web-Based O&M Manual

Historically, the use of O&M manuals has been the first option for maintenance and troubleshooting for the operator.  In the past ten years, component manufacturers with standard products have begun to offer their manuals via web access.  Our engineers and service technicians made use of this offering by frequently downloading a specific manual online for troubleshooting an equipment issue.

Still, most system integrators or custom manufacturers like Envitech have only delivered "binder" manuals or large PDF electronic files.  The problem with this approach is that the "binder" manuals are not very portable or sortable and often get lost or damaged.  Large PDF electronic files are often electronically misplaced and forgotten.  The result is that operators are scraping ID tags for model numbers or replacing equipment without a thought to troubleshooting or repair.

Seeing the ease of use online manuals from component manufacturers has provided, Envitech challenged itself to produce an online manual for its custom manufacturered equipment.  Starting with projects ordered in 2015, Envitech has produced an online manual for its customers.  The feedback to date has been positive, and we intend to extend this benefit to all customers via our service plan.

If you are interested in learning more about our Service Program and other features and benefits of using Envitech for your scrubber maintenance, press the buttom below.

Contact Envitech Service

Topics: Scrubber Service

Scrubber Service and Maintenance

Posted by Andy Olds on Mon, Oct 19, 2015 @ 11:00 AM

Envitech Service TeamEnvitech is proud to launch a new scrubber service and maintenance program for all users of air pollution control equipment.  Envitech offers the program to provide plant managers, environmental departments, plant engineering and operations and maintenance staffs access to our trained, experienced group of engineers and technicians.  Our goal is to improve your uptime, reduce your operating costs, ensure you meet compliance and offer you an on-demand technical resource for troubleshooting your equipment.  Additionally, we want to help you organize your maintenance programs and provide training to keep your operators up to date.

Over the past year we have strengthened our service department with technicians, tools, and training. In so doing, we have provided new and varied service to our existing customers.  For example we have:

  • Tuned a medical waste incinerator remotely to minimize CO emissions and to reduce fuel usage
  • Calibrated pH and conductivity probes prior to a successful stack test
  • Rescaled a replacement transmitter after the existing model was discontinued
  • Added HMI screens to permit trending of critical instruments
  • Upgraded VFD, PLC and HMI software to improve security of Ethernet controlled equipment
  • Precoated new cartridge filters and used Visolite to detect for filter breaches

As part of the program we offer the following services:

Our service program is built for the following equipment:

  • Quenchers
  • Packed Bed Absorbers (Scrubbers)
  • Condensers
  • Venturi Scrubbers
  • Collision Scrubbers
  • Entrainment Separators
  • Wet Electrostatic Precipitators
  • Fans
  • Cartridge Filters
  • Carbon Beds

Additionally, we maintain key relationships with other pollution control suppliers to help you service equipment such as:

  • Regenerative Thermal Oxidizers (RTO)
  • Medical Waste Incinerators
  • Hazardous Waste Incinerators
  • Afterburners
  • Thermal Oxidizers
  • Baghouses
  • Dryers
  • Cooling Towers
  • Oxidations Systems
  • Wastewater Treatment

If you are interested call or email Envitech today.

Contact Envitech Service

Topics: Scrubber Service, WESP Service

Ceramic Tile Kiln Acid Gas Scrubber: HF, HCl, SO2

Posted by Andy Bartocci on Thu, Oct 15, 2015 @ 04:38 PM


A Midwestern ceramic tile manufacturer needed an acid gas scrubber to treat the off gas from 3 kilns being installed at a new manufacturing plant. Each kiln was equal in size and emits HF, HCl, and SO2. The scrubber needed to remove > 98.5% of acid gases. The scope of supply included an ID Fan, interconnect duct, stack, control system, and pump skid. The facility was faced with the additional challenge of less than 22 ft of overhead space inside the building. A tight schedule required receipt of equipment in 16 weeks, including engineering. The customer operated other scrubbers at different facilities and reported difficulty in controlling the spray quenchers to cool and saturate the gas.


The customer selected an Envitech quencher/packed bed scrubber to meet their requirements. To eliminate difficulty in controlling gas cooling the scrubber used a proprietary, low pressure drop Venturi quencher. This provided a means to saturate the gas over a wide range of operating conditions and flow rates. The scrubber used a proprietary internal duct design with an outlet and entrainment separator at the bottom of the scrubber. This allowed the scrubber to fit in the low overhead space with no roof penetrations to minimize installation cost and time. Other equipment features included:

  •  Quencher design to capture > 90% of particulate > 3 microns.
  • Skid mounted dual pumps (1 opr/1 spare) with pre-piped and valved instruments.
  • Hydro-testing of piping assemblies.
  • Instruments pre-wired to a junction box.
  • Control System Factory Acceptance Test (FAT).
  • High efficiency, low pressure drop packing with high void spaces to prevent material accumulation and fouling.


The customer placed the order in June, 2015. The equipment shipped on time in October 2015 and arrived on site one week early, 15 weeks from order placement. The system will be operational in early 2016. Stack testing will confirm compliance with the performance guarantee summarized in the table below.



Flow Rate, acfm


Inlet Temp, oF


HF Removal

> 98.5%

HCl Removal

> 97%

SO2 Removal

> 53%

 To download a Free Case Study, please click on the icon below.

Download Case Study




Topics: Scrubbers, SO2 Scrubber, Acid Gas, quenchers

IT3/HWC 2015 Conference October 20-22, 2015 – Wet Electrostatic Precipitator for Medical Waste Incinerators

Posted by Andy Bartocci on Tue, Sep 22, 2015 @ 01:47 PM

Envitech will attend the International Conference on Thermal Treatment Technologies (IT3/HWC), October 20-22, 2015 at the Crowne Plaza Hotel in downtown, Houston, Texas.  The preliminary technical program can be downloaded from the conference website.   The conference features key note speakers from Veolia, Clean Harbors, Essroc, TCEQ, and B3 Systems.

Envitech will have an exhibit booth and present a paper, “Meeting the New Hospital, Medical, and Infectious Waste Incinerator (HMIWI) MACT with a Wet Electrostatic Precipitator (WESP)”.  The paper will provide an overview of a new medical waste incinerator scrubber system with a wet electrostatic precipitator to treat the off gas from two existing medical waste incinerators. The new system was required to achieve a 20% reduction in particulate (PM) emissions, and a 93% reduction in lead (Pb) emissions from the previous gas cleaning system.  The new system has been operational since October 2014.  The table below compares the performance of the emission limits to the new compliance standards. The results demonstrate the system comfortably meets the new EPA MACT standards.







Test Result

% of limit

Particulates, EPA Method 5 gr/dscf 0.020 15%
Pb EPA Method 29 mg/dscm 0.018 6%
Cd, EPA Method 29 mg/dscm 0.013 10%
Hg mg/dscm 0.025 1.0%
Dioxins/furans, EPA Method 23 Total (ng/dscm) 0.85 5%
  TEQ (ng/dscm) 0.020 15%
HCl, EPA Method 26 ppmv 7.7 1.6%
SO2 ppmv 4.2 35%

Click on the icon below to download a copy of the paper.


Topics: particulate control, Venturi scrubbers, wet electrostatic precipitators, MACT Standards, Medical Waste Incinerator Scrubber, Incinerator Scrubber, HMIWI Scrubber

Rectangular Acid Gas Scrubber Lowers Installation Cost and Improves Maintenance

Posted by Andy Bartocci on Thu, Jul 09, 2015 @ 03:29 PM

Acid gas scrubbers are one of the most common types of air pollution control systems found in industry.  They are often used to treat exhaust gases from combustion sources such as incinerators, hazardous waste combustors, thermal oxidizers, regenerative thermal oxidizers (RTO), furnaces, and direct fired heaters.   Acid gas scrubbers are found on a wide range of facilities including, geothermal plants, secondary lead smelters, waste oil re-refiners, refineries, chemical and pharmaceutical plants, and mineral and metal processing facilities.  The most common types of acid gas emissions are HCl and SO2, but can also include Cl2, HBr, HF, and NOx.

Most acid gas scrubbers are wet scrubbers using vertical packed bed absorbers.   In the case of combustion sources, the scrubber is coupled to an evaporative quencher to cool the gas to saturation before it passes to the packed bed. This arrangement is shown in the adjacent figure for a medical waste WSU_Vertical_Scrubberincinerator.  The incinerator exhaust is ducted to a metal quencher (shown in the foreground). The hot gas enters the top of the quencher and flows vertically downward. The gas then elbows into the bottom of a vertical packed bed scrubber (shown in the background). The gas passes upward through the packed bed as re-circulated water flows downward, counter-current to the gas from the top of the packed bed.  Water from the quencher and packed bed is collected in the sump and re-circulated back to the quencher and packed bed.  An entrainment separator at the top of the scrubber removes entrained water droplets.  After exiting the scrubber vessel, an interconnect duct transports the gas to a induced draft fan located at grade.

The scrubber above is one of the earliest Envitech medical waste incinerator scrubbers.  These types of scrubbers are often installed in hospitals where critical design considerations include limited space, low ceilings, and difficult to reach locations through elevators and narrow corridors.  To help minimize installation costs Envitech developed a rectangular scrubber which is shown in the figure below. 













This configuration provides several advantages over a vertical scrubber, including:

Greater integration and pre-assembly of ancillary equipment and pumps, piping, valves, and fittings.

  • Ground level access manways for safer, easier maintenance.
  • Simplified ductwork connection to the fan and stack.
  • Elimination of caged ladders and platforms for nozzle and mist eliminator access.
  • Ability to fit in locations with low head space.
  • Simplified requirements for setting and integrating equipment which lowers installation costs.

The rectangular scrubber has been used on over 60 installations.  Envitech has found that facilities tend to prefer a rectangular design over a vertical scrubber for the advantages noted above.  In some cases, total installed cost is reduced by 40% to  50%.  Weather a scrubber is purchased from an EPC contractor, upstream equipment supplier, or architectural & engineering firm, it is recommended that facility preferences be taken into consideration in the final selection process.

The video link below shows a few recently installed rectangular scrubbers at waste oil re-refiners as well as several examples of other rectangular scrubber installations.


Click the link below for a free case study on  a rectangular acid gas scrubber for a direct fired heater at a waste oil re-refiner.


Click the link below for a free case study on a rectangular medical waste incinerator scrubber for the control of acid gases, particulate, and heavy metals.


Topics: Scrubbers, SO2 Scrubber, Acid Gas, HMIWI Scrubber

Refinery Sulfur Recovery Unit (SRU) SO2 Scrubber for Startup, Shutdown, and Malfunction

Posted by Andy Bartocci on Wed, Jun 24, 2015 @ 05:55 PM

For years, many states have exempted industrial facilities from rules prohibiting the release of toxic pollution during startup, shutdown, and malfunctions. That could all soon change.  On May 22, 2015, the U.S. Environmental Protection Agency (EPA) finalized a rule which will force state regulators to limit industrial upset emissions. The EPA issued a state implementation plan (SIP) call action to 36 states directing them to correct specific startup, shutdown, and malfunction provisions in their SIPs to ensure they are fully consistent with the Clean Air Act (CAA).  The ruling will affect a wide range of facilities including refineries, chemical manufacturers, and natural gas producers.  This will create challenges for state regulators and industrial facilities and opportunities for technology providers and environmental consulting and engineering firms.

A common industrial application which may be impacted by the new rule is found in refineries for sulfur recovery units (SRU).  Most SRU’s are based on a multi-step Claus process which recovers sulfur from gaseous hydrogen sulfide. The hydrogen sulfide is found in by-product gases from refining crude oil and other industrial processes.  A Tail Gas Treatment Unit (TGTU) follows the SRU to recover sulfur and return it to the SRU.  A TGTU can yield 99.9% sulfur recovery for a typical oil refining plant.  An in1110_-_Sinclair2cinerator and waste heat boiler treats the TGTU off-gas before it is exhausted to atmosphere. 

During normal operations, there is very little SO2 emissions due to the high sulfur recovery. However, TGTU upsets can occur several times per year which sends unrecovered sulfur to the incinerator.  During these upsets, SO2 emissions can be as high as 1 tph  or more for a period of 8 to 12 hours.

Envtech is designing a refinery standby SRU tail gas caustic scrubber which will eliminate SO2 emissions during upset conditions.  The scrubber uses Envitech’s proprietary quencher which acts as a low pressure drop Venturi. The quencher is  followed by a packed bed absorber for SO2 removal.  The overall pressure drop is less than 10 inches and has lower power consumption than other types of SRU scrubbers installed in refineries.   Special design considerations enable the exhaust gas to pass through the scrubber at both elevated and cool temperatures.  During normal operation, hot gas from the TGTU passes through the scrubber in standby mode with the re-circulation pumps turned off.  In this mode, the gas is at elevated temperatures of 500oF to 600oF.  During a trip event, the TGTU is bypassed and the recirculation pumps turn on automatically.  The gases are then cooled to saturation and SO2 is absorbed and removed in the packed bed.  Implementation will enable to the facility to reduce SO2 emission by 40 to 80 tpy and to meet the new EPA compliance standards for start-up, shutdown, & malfunction.    The scrubber is a good example of how an innovative solution can help a facility meet the new emission requirements during upset conditions with significant benefit to the environment.

Topics: Scrubbers, SO2 Scrubber, Acid Gas

Medical Waste Incinerator Scrubber Used to Process Ebola Waste

Posted by Andy Bartocci on Wed, Nov 05, 2014 @ 08:43 PM

Envitech recently got noticed in a local news story by Michael Chen of Channel 10 News, “Local Company Helps Dispose of Ebola-tainted Waste”.  The story talks about the challenges of processing Ebola waste and how Envitech’s Medical Waste Incinerator Scrubber at the University of Texas Medical Branch (UTMB) was used to dispose of waste generated by an Ebola patient in Texas.

UTMB operates the only permitted medical waste incinerator in the state of Texas.  Since 1991 the facility has operated an incinerator which uses an Envitech wet scrubber system to clean the exhaust gases of harmful pollutants.  A new incinerator system was recently installed to meet the new EPA rules promulgated for the hospital, medical, and infectious waste incinerator (HMIWI) maximum achievable control technology (MACT) standard.  The impact of these rules is discussed in a previous blog post.

The outlet emission requirements of the new standards are a significant reduction from the previous 1997 standards.  The allowable outlet emissions for many of the metals, i.e. lead (Pd), Cadmium (Cd) are less than 1% of the previous emission limits. For example, the allowable concentrations for Pb,and Cd are measured in 10-7 and 10-8 gr/dscf, respectively.  These are some of the lowest HAPs emission limits for industrial sources in the United States. Medical Waste Scrubber Below is a summary performance guarantee for the new scrubber system based on the new HMIWI standard:

  • PM < 18.3 mg/dscm (0.008 gr/dscf)
  • Lead < 0.00069 mg/dscm (3.0 x 10-7 gr/dscf)
  • Cd < 0.00013 mg/dscm (5.7 x 10-8 gr/dscf)
  • HCl < 5.1 ppmv dry
  • SO2 < 8.1 ppmv dry
  • Dioxins/Furans < 0.035 ng/dscm on TEQ basis

Recent episodes of processing highly infectious waste from Ebola patients may re-ignite a policy debate on medical waste disposal. In the early 1990, many hospitals were going to a model of owning and operating a relatively small medical waste incinerator to process and destroy medical waste generated in-house. These systems typically have a capacity of 500 to 1,500 lb/hr. As air emission standards became stricter, many hospitals decided to shut down their incinerators and ship their waste to larger, centralized medical waste incinerators. These systems are much larger in capacity. For example, the largest medical waste incinerator facility is in Baltimore, MD with a permitted capacity of 150 ton/hr. The trade-off of a centralized waste incinerator is the risk and liability of transporting the waste on public roads and highways. The recent Ebola outbreaks bring to light that some of this waste can be highly infectious and pose a significantly greater risk to public health. It also came to light that a single Ebola patient generates a substantial amount of infectious waste. In this scenario, it may make more sense for facilities to have the capacity to destroy their own waste and avoid the risk of transporting it over great distances on public roads.

The advancement of scrubber technology and compliance with the new, more stringent EPA MACT standards, confirm the ability to operate medical waste incinerators with virtually no harmful emissions into the air.  In addition to the UTMB medical waste scrubber system, Envitech has upgraded several other medical waste incinerators for meeting the new standards.  Based on the extreme low emission limits, the results are truly groundbreaking and may encourage states and facilities to permit new systems.

Topics: Venturi scrubbers, MACT Standards, Ebola Waste, Medical Waste Incinerator Scrubber, Incinerator Scrubber, HMIWI Scrubber

Marine Diesel Scrubber Passes CARB Testing

Posted by Andy Bartocci on Mon, Jan 13, 2014 @ 07:04 PM

Marine ScrubberIn 2012 Envitech designed and built a marine diesel scrubber to remove SO2 from the engine exhaust of ocean going vessels.  The scrubber was integrated into the Advanced Maritime Emissions Control System (AMECS) used at the Port of Long Beach.  AMECS is a stationary system that uses a bonnet to capture the exhaust gas from the ships stack while at port. The exhaust gases are conveyed to AMECS to clean the gases of particulate (PM), NOx and SOx before exhausting to atmosphere. This allows the ship to operate its auxiliary engines and boiler system while at port to provide power to the ship.  AMECS provides a cost effective way for ships and port operators to reduce emissions and to meet tougher regulatory standards. 

The AMECS team recently announced that the California Air Resource Board (CARB) has approved AMECS as an alternative technology for the At-Berth Regulation.  This approval follows more than 1500 hours of validation testing on 40+ vessels during 2012 and 2013.  The most recent testing occurred in October of 2013 and was attended by representative of CARB and SCAQMD as well as representatives from the Ports of Long Beach and Los Angeles.  The test yielded impressive results, including:

    • PM                                                                  94.5%
    • NOx (@1.6ppm ammonia slip)                       99+%
    • SO2                                                                 98.5%
    • VOCs                                                              99.5%

In a parallel track, the maritime industry is looking for ways to meet tougher standards not only at port but while operating at sea based on the IMO Annex VI MARIPOL Tier III requirements. Envitech continues to develop De-SOx technology options for ship based marine diesel engines.  The recent CARB approval is a milestone achievement for demonstrating the Envitech scrubbers ability to achieve high SO2 removal efficiency over a wide range of diesel exhaust and operating conditions.

Click on the link below to download a case study on the marine scrubber.

describe the image




Topics: Scrubbers, SO2 Scrubber, Marine Scrubber

Arsenic Scrubber for Copper Mine Roaster

Posted by Andy Bartocci on Thu, Jan 09, 2014 @ 04:00 PM

With an expanding global population, demand for minerals continues to grow.   Development of non-traditional resources is expected to increase to meet this growing demand. This includesCopper Mine copper resources challenged by high levels of arsenic.  Mining operations may incur penalties for arsenic in concentrates that exceed a certain amount.  As ore with low levels of arsenic is depleted, these penalties will continue to rise.

One facility seeking to reduce the impact of penalties is the Aranzazu project in Zacatecas Mexico by Aura Minerals.  The facility will use a partial roasting technology by Technip to achieve arsenic reduction in the concentrate.  After treatment, the concentrate is expected to contain less than 0.3% arsenic.  This will decrease expected arsenic related penalties by up to $1.00 per payable pound of copper produced.

wet electrostatic precipitator


The roaster off-gas will be treated by an Envitech wet scrubber system to remove arsenic with a 99.9% performance guarantee. The inlet gas to the scrubber will be at an elevated temperature well above 1,000oF and will have a high concentration of particulate, sulfur, and arsenic. The scrubber system combines Envitech’s wet scrubber technology which has been used to remove hazardous air pollutants from medical and hazardous waste incinerators with Envitech’s wet electrostatic precipitator technology (WESP) for final collection and removal of arsenic.  Envitech’s WESP technology has demonstrated high performance for arsenic removal on other furnace applications at secondary lead smelting facilities.



Topics: Venturi scrubbers, wet electrostatic precipitators

    Subscribe to our blog

    Ask an Expert