Testing the water: Hatch goes mobile

Ailbhe Goodbody caught up with Andrew Kasza, process engineer at Hatch, to talk about the company’s mobile water testing capability and its benefit for both new and operating mine sites
Testing the water: Hatch goes mobile Testing the water: Hatch goes mobile Testing the water: Hatch goes mobile Testing the water: Hatch goes mobile Testing the water: Hatch goes mobile

High-throughput testing set-up

Ailbhe Goodbody

Could you tell me a bit about Hatch’s mobile water testing?

The mining industry continues to be influenced by a changing world economy and our clients have responded by focusing on operational excellence and financial discipline. Value is created by finding new ways to improve the productivity of existing assets. This includes improvements to site-wide water usage and water treatment processes.

Hatch’s mobile lab was developed in response to our client’s focus on operational excellence and process improvement. The testing capabilities have recently been used for the following: process troubleshooting at their existing water treatment plants; process support and/or optimisation of an operating process to decrease operating costs and improve operability; and proof of concept at a bench scale of various technologies in support of new capital expenditures on the water treatment side of things.

What are the advantages of mobile water testing?

The first advantage is that the testing capabilities are mobile. This allows our team to visit a mine or mineral processing site and bring our testing equipment with us. We interact face-to-face with our client and really get to understand the site-specific water challenges by having boots on the ground.

When dealing with complex mine waters, variations in water quality often occur. These variations may be seasonal – for example an increase in turbidity due to run-off – or can be process-related and result in significant changes to water quality over a short timeframe.

Another advantage is that water testing can be completed under field conditions. Water chemistry changes associated with shipping samples offsite and sample-storage conditions are eliminated. This is particularly important for waters that may be in saturated conditions where fluctuations in temperature can cause precipitation to occur prior to testing. Our ability to be at site and collect and test a water sample directly from the process allows our team to get the most representative results for our client.

We also use high-throughput testing methodologies whenever possible for water tests. The high-throughput methodologies we have developed allow our team to run significantly more tests while minimising the amount of raw water sample required. The high-throughput approach maximises the amount of data that can be collected and allows our engineers to investigate many treatment alternatives and/or chemical recipes. Versus a more conventional testing approach, we are able to more efficiently drive towards an optimal solution.

Finally, process engineers specialising in water treatment develop the site-specific test plan and then mobilise to site to complete the testing. Our team of process engineers are able to work directly with our client’s site team. This results in tailored water testing in support of project development or troubleshooting/optimisation of an existing plant.

What are its capabilities, and what equipment is included?

The equipment that we have included in our mobile lab allows us to complete various bench-scale water tests, including coagulation/flocculation/precipitation, oxidation, filtration, and ion exchange in both a batch and continuous arrangement. The mobile lab is intended for on-site bench-scale investigations and does not replace long-term pilot programmes at scale.

One of the differentiators is the previously mentioned high-throughput testing methodology that we employ. This is primarily used for coagulation/flocculation/precipitation studies. Compared to the conventional jar testing method where four or six one-litre samples are tested, our method is able to test up to 48 samples simultaneously at various dosing and chemical combinations. All of this is accomplished by a high-throughput testing apparatus and procedure developed in-house.

Also included in the mobile lab are portable analytical instruments that provide our engineers with the ability to complete basic analytics in the field. A turbidimeter and colorimeter, among others, allow for quick determination of parameters such as turbidity and total/dissolved metals. Having results in real-time helps to guide the overall test plan. Analytical results collected in the field are then verified in a lab.

What sites would it typically be suitable for?

The mobile lab is applicable for any site treating or managing water that requires on-site testing for proof-of-concept, troubleshooting, or optimisation studies. For example, our mobile lab has recently been deployed for projects at gold, copper, lead and zinc mines. Outside of mining, the mobile lab has been deployed to industrial sites, including pigment production and steelmaking.

We have a number of case studies for heavy metals removal by precipitation/co-precipitation using different coagulants and flocculants.

Has there been increased interest in recent years from mining companies in this sort of technology?

Yes, absolutely. Mining companies are continuing to improve existing assets and reduce operating costs, especially for water treatment. Additionally, for those mining companies that may be undertaking significant capital expenditures to build a new water treatment plant, the ability to investigate various process alternatives in a cost effective manner by completing bench testing is always attractive. Our ability to complete this type of testing at site, side-by-side with our clients, is a real benefit.

What would Hatch recommend to potential mining customers that are interested in mobile water testing?

At minimum, every mine manages water. Efficient and sustainable water usage is fundamental for all water-based mining operations to maintain a social license to operate. When treatment is required, doing so in the most cost-effective manner is essential.

Our water testing capabilities have thus far been offered to our clients as a service. Hatch is contracted to organise and conduct the testing and provide recommendations in support of the project. As previously mentioned, our clients have highly valued having specialised water treatment engineers complete the testing at site using the mobile lab. We feel this is a differentiator for us. Alternatively, mining companies may see value in developing mobile testing capabilities for in-house water testing. The team is open to supporting a client in developing their own mobile testing lab, but has not yet been requested to do so.

Do you have any recent examples of mine sites where Hatch has supplied this technology?

In the short time the mobile lab has been offered, Hatch has identified significant savings potential for clients operating existing water treatment plants. One such mining client contracted us to use our high-throughput methodology to evaluate various combinations of water treatment chemicals to treat tailings reclaim water. In three days we ran 425 distinct tests using different chemicals at different dosages and were able to recommend a chemical recipe that, if actioned, was estimated to reduce operating costs by up to C$2 million (US$1.5 million) per year.

Another recent project was in the southwestern US. The client was operating an existing water treatment plant to recover process reagents from a complex water stream. The water treatment plant was experiencing unforeseen operational challenges and higher than expected operating costs. Instead of modifying the water treatment plant, recommendations were presented to stabilise the upstream processes to reduce variability and solids load to the water treatment plant. In this case, the mobile lab was deployed to support the recommendation to modify tailings management and reclaim water management practices.

Were there any challenges encountered, and if so how were they overcome?

The biggest challenge that we find is getting representative samples at the right point in time when we’re on site. That’s another thing that needs to be considered when developing the test plan before we mobilise. Typically, clients contact us because they have a problem or they want to decrease costs, but mining operations vary quite a bit in terms of water quantity and quality throughout the seasons.

One of the challenges we have experienced is changes to water quality. During our planning we strive for good communication with our client so that we can understand the challenge as best as possible before we build the test plan and go to site. We very much prefer to conduct testing at site to minimise changes to the raw sample. This way we can ensure that testing is completed on the most representative water sample. That said, we are also able to accept and test water samples remotely here in Canada if it is deemed to be the most feasible approach.

Does Hatch have any future installations planned at mining operations?

We anticipate helping a client in Peru with a high-density sludge (HDS) system for treatment of acidic mine drainage. This project will be bench-scale testing to optimising the HDS precipitation process.

Do you see this as an area of expansion for Hatch?

Absolutely, we are seeing interest from our clients to complete testing and gained a lot of traction in 2016. We are continuing to focus this offering in the mining industry, but are also expanding to other industrial and municipal applications.

We have also begun using the mobile lab to support in-house research initiatives, such as technologies and methods for ammonia removal from mine waters and treatment of oil sands tailings. Hatch is in the process of establishing bench-scale membrane testing capabilities for project work and research as well.

Is this a global offering?

Absolutely. So far we’ve deployed within Canada, multiple places in the US, and Peru. We are actively looking for other opportunities in North and South America and will also be visiting South Africa for a symposium in May. Hatch takes pride in supporting our clients wherever they operate in the world.