Tackling corrosion in mining processes with Fiber Reinforced Polymer

Corrosion can simply be defined as the destructive oxidation of metallic material. But more recent definitions of corrosion have include the degradation of any material and its intended loss of function by exposure to and interaction with its environment.

Corrosion in the mining industry is often characterized as corrosion enhanced by abrasion—this is especially true for pipe and pumping systems used in many mining processes. Material selection is therefore a critical component of most corrosion management strategies. to-weight ratio, durability, and low maintenance costs—among other things. FRP products have been employed effectively in a diversity of applications, including pulp and paper, chemical processing, power generation, wastewater management, desalination, aerospace, architectural, food and beverage, and mining and minerals— among much else.

Fiberglass

Fibreglass or Fiber Reinforced Polymer (FRP) is a complex non-isotropic material, in which two or more distinct, structurally complementary substances, glass fiber and thermoset polymer resin, combine to produce structural or functional properties not present in the individual component.

Used throughout the world in a wide range of industrial and nonindustrial applications, FRP boasts cost-effectiveness, design flexibility, dimensional stability, high strengthFRP continues to gain in popularity as a material solution for pump and piping systems in the mining and mineral industries. And this is because they can

be made to be: Compliant for potable water, Fire retardant, Abrasion resistant, Impact resistant, Electrically conductive, Heat resistant up to 450F, Corrosion resistant – acids, caustics and UV resistant.

Fibreglass Design

Some of the information required for FRP design include the: structural loading, chemical resistance required, temperature, seismic loading and wind loading.

Fiberglass fabrication

Since they are produced as “wet” material that is then cured to provide the hardness required, Fiberglass products are prepared on molds.

FRP when designed properly is a cost-effective material that has demonstrated its durability and ability to withstand industrial conditions, but also, importantly long-term environmental exposure—a key distinction that has interested many civil engineers involved in the rehabilitation, retrofitting and complete rebuilding of bridges, other load bearing structures and or architectural elements, such as, prestressing tendons, reinforcing bars, and grid-reinforcements and structural columns. Regardless of what type of project type or project environment you are planning for there are likely supporting case studies available that demonstrate the opportunity, solutions and benefits realized when integrating FRP into project design.

Tanks, pipe and duct are made on “male” molds, with the fiberglass applied to the outside of the mold. Per FRP standards, dimensions are based on the internal diameters of the finished parts.

The first layers on the mold are the most critical for corrosive environments. These typically consist of a corrosion resistant veil followed by 2 to 3 layers of random mat to provide a resin-rich100 to 125 mil corrosion liner. Plastics such as PVC, polypropylene and Viton can also be used for the internal barrier.

Fiberglass brings versatility to the table—among much else including light-weight, high strength-to-weight ratio, it can also be designed to meet vacuum specifications—an important component in some wastewater applications. Fiberglass applications in the wastewater or water purification industry include, but are not limited to, chemical water treatment, industrial waste water treatment, lime-soda treatment, chlorine, disinfection, clarification, demineralization, oil demulsification, metal precipitation, odor, control, bioaugmentation, and the processing/handling/storage of many chemical precipitants, coagulants, flocculants, and defoamers.

Fiberglass materials formulated from high quality epoxy vinyl ester resins will outperform stainless steel in chemically aggressive environments including Sulfuric Acid. For example, in dilute form sulfuric acid is known to be extremely corrosive to carbon steel, yet properly formulated fiberglass can provide corrosion resistance.

FRP Composition

There are four main ingredients that FRP are comprised of: resins, reinforcements, fillers, and additives/modifiers. Each ingredient is equally important and all ingredients play an important role in determining the properties of the finished FRP products. To simplify, think of the resin (polymer) as the glue or the binding agent. The mechanical strength is provided by the reinforcements.

Resins

The primary functions of the resin are to transfer stress between the reinforcing fibers, act as a glue to hold the fibers together, and protect the fibers from mechanical and environmental damage.

Reinforcements: Fibers and Forms Generally speaking there are four common types of fibers broadly used in the FRP industry: glass, carbon, natural, and arimid. Each has their advantages and applications. Similarly, reinforcements are available in forms to serve a wide range of processes, service and end product requirements.

Fillers

Fillers are used as process or performance aids to impart special properties to the end product. Some examples of inorganic fillers include calcium carbonate, hydrous aluminum silicate, alumina trihydrate, and calcium sulfate.

Additives and Modifiers

Additives and modifiers perform critical functions despite their relative low quantity by weight when compared to the other ingredients such as resins, reinforcements and fillers. Some additives used in thermoset and thermoplastic composites include: low shrink/low profile (when smooth surfaces are required), fire resistance, air release, emission control, viscosity control, and electrical conductivity.

Crimar Industrial:

A leader in fiberglass industrial Equipment manufacturing

For over 30 years, Crimar Industrial has been providing high quality fiberglass industrial equipment (tanks, piping, ductwork, thickener covers, process equipment, custom fabrication, and field installation and maintenance services) to mining, municipal, petro-chemical and other industrial applications around the world.

Through their sister company, Shijiazhuang Beman Commercial Co. Ltd. (SBC) which handles sourcing and project management in China, the company can negotiate and enforce contracts with all the rights and privileges of a Chinese company and provide complete quality control and expediting services.

With a strong customer base which includes companies such as: WesTech, FLSmidth, Glencore Mining, Hatch Engineering, CODELCO, Freeport McMoRan, Jacobs Engineering, ASARCO, M3 Engineering, IMC Kalium, Abbott, Labs, Intrepid Potash, Siemens/ US Filter, Biorem, Grupo Mexico among others, Crimar Industrial/SBC continues to be a major player in the industry.

Crimar Industrial/SBC also utilises top notch expertise both internal and external during the design stage of their products to ensure high quality products.

“While we have extensive internal expertise in fiberglass design and fabrication, we also have the full support of the design center at our subcontract facility in as well as of Professional Engineers in the US and Canada that specialize in fiberglass design and inspection services,” says company president Roger Beman.

All design, fabrication and inspection is in accordance with international standards such as ASME RTP-1, ASTM 3299, ASTM 4097.

As a testament of their rigorous internal QC, most customers have accepted in-house QC inspections as sufficient evidence of compliance. But when appropriate Crimar also contracts or coordinates with internationally known third party inspection companies such as Moody, Veritas, TUV Rheinland, and others to provide certified inspection reports of materials, production procedures, dimensions, and overall compliance with the terms of the contract.

To serve their customers better, Crimar Industrial/SBC have sales & support offices in Tucson, Arizona; Toronto; Santiago; Lima; Shijiazhuang; Johannesburg; and Medellin in Colombia. Their office in China (Shijiazhuang Beman Commercial Co. Ltd.) provides complete sourcing, QC, import - export and expediting.

Key to their success has been in assisting customers by understanding their requirements, assisting them in design when appropriate, and the delivery of high-quality products on time for a competitive price.

In fact, Mr. Beman, the President and Owner of Crimar Industrial and majority owner of the Shijiazhuang Beman Commercial Co. Ltd. (SBCCO-China) has been traveling to China an average of 10 times a year for the past 15 years to ensure that suppliers understand and meet customers’ needs.

Products and services at a glance • Fiberglass Reinforced Plastics (FRP) Products • Steel Pipes & Fittings • Crushing and Milling Equipment and Wear Parts • Casting & Forging • Steel Process Equipment • Custom Fabrication - Steel and

FRP • Dampers & valves • Solid/Liquid Separation Equipment • Project Management

For further information see • www.crimar.com • www.sbcco-china.com

There are many different kinds of glass fiber to provide a wide variety of laminate strengths: • Glass fiber • Carbon fiber • Bamboo fiber

And different textures

• Winding glass • Chopped strand glass • Woven glass • Unidirectional glass • Corrosion veil •

FABRICATION METHODS

• Filament winding • Chopper gun • Hand lay up • Resin Transfer • Pultrusion

FRP DESIGN

Some of the information required for FRP design include the: • structural loading • chemical resistance required • temperature • seismic loading • wind loading

When appropriate we prepare finite element analyses (FEA’s) to model the design and loads to ensure that the project requiremenst will be met

We can help you from the beginning of the project through completion. We can assist with the design, fabrication, and shipping of the products sold. Where appropriate we can also provide on site fabrication or assembly. Once the installation is complete, we can provide ongoing support and maintenance services.

For further information please contact Zish Zhao at zishzhao@sbcco-china.com

Phytomining

Author: Harshvardhan singh, works as a senior service engineer at a mining firm in India

Mining is a tough place to work in. My career transition from a tribology research-based job in Austria to a service-oriented job involving heavy earth moving machines, inside underground mines in India, was difficult in the beginning but my inner automotive engineer help me adapt to the workplace. In a short but adventurous work tenure in mining industry, every single work on machine whether in underground or on surface, focused on “Safety first” or “My safety my responsibility” moto. Considering the hazards and risks involved in mining, the above safety moto should be followed by everyone working in any mines.

As we are all aware of; mining serves as the primary source of minerals that countries discover to satisfy needs such as manufacturing of electronic and electrical appliances, construction of transportation network, power generation, job creation and many other things that grows in demand with rising population, urbanization and income growth. It can be said that mining is the

Impact of mining

Environment • Water quality and availability of water resources within the mining area and nearby regions. • Gas emissions from combustion of fuels in stationary and mobile sources and particulate matter dispersed in air due to blasting and excavation. • Noise pollution from mining equipment’s and vibrations affecting stability of infrastructures. • Soil contamination affecting agricultural activities. Social • Migration • Livelihood loss Wildlife Habitat loss Climate change High carbon uptake into the environment Health Exposure of worker to occupational hazards starting point of every supply chain. Given that mining plays an important contributor to goods and services that consumers enjoy in their day to day life, it also has drawbacks; that is its negative impact on environment, social and cultural values, climate change and health of workers.

The growing demand of minerals and considering the harsh effects of mining as listed in Table 1., exploration of sustainable environmental-friendly technologies to mine minerals have begun. One such evolving technology is Phytomining. Rufus Chaney, an agronomist at the U.S. Department of Agriculture is widely credited for inventing Phytomining in the year 1983. As a token of recognition for his research findings, a hyperaccumulator plant capable of absorbing Nickel has been named after him – “P. rufuschaneyi”

In order to understand concept of Phytomining, we need to first become familiar with the term Hyperaccumulation. The term can be broken down into two parts – hyper meaning excessive and accumulation meaning to gather a quantity or mass. Hyperaccumulation can be referred as the ability of a plants to absorb, tolerate, traffic and store elevated amount of heavy metals from root to leaves. The associated plants are referred to as hyperaccumulators. More than 450 species of plants have these hyperaccumulation genes (HA genes).

The process starts with growing hyperaccumulator plants in regions containing metal rich soil, it can be a fresh land or contaminated land. Land surveys for minerals can help us choose the type of plant that would be suitable to grow in the region. Next comes absorption of metal by roots provided the metal has dissolved itself in the soil in the form of ion. Absorbed metFigure 2. Metal hyperaccumulation als are then transported from roots to shoot via metal transporting proteins. Metals are then stored in in stem and leaves. Metal extraction starts with chopping and drying of leaves. The dry mass is then put inside a reactor along with some quantity of water. This results into generation of biogas and breakage of cell walls. The output is a wet mass which is then dried in an oven and further processed to yield metal.

Since we are now familiar with the process, lets discuss some pros and cons of Phytomining.

Figure 3. Model representing Phytomining process

Advantages of Phytomining

• Can be utilized for areas having low mineral reserves, where commercial mining won’t be sustainable. • The process is environmentally friendly. • Higher amount of concentration can be achieved. • Quantity of waste disposal is low.

Disadvantages of Phytomining

• Process is slow as crops can take years to grow. • Dependency on weather, soil type and other growing conditions. • Large scale harvesting hyperaccumulator plants proves to be expensive.

Phytomining is still in developing stage. Genetic modification of plants to increase metal uptake, fertilizers to protect these crops from pests, suitable environment and condition to grow these crops, are few areas which require further investigation that will help this technology to switch to commercial scale.