Case Studies

FRP Has Rich Future in Mineral Processing

| By jroberts | In Case Studies |

Mining activity in a number of basic metals and minerals has been running quite high over the last few years. Historically high commodity prices for metals and minerals spurred on by rapidly rising worldwide demand for raw materials are heating up both organic growth projects and merger & acquisition activity. The world needs resources to meet explosive growth in developing nations and to supply the ongoing high level of demand in developed nations.

The world’s largest nickel mine – the massive $4.76 billion Ambatovy nickel mine on the African island nation of Madagascar is nearing completion. When it reaches its full production capacity in 2013, the mine will produce 60,000 MT/yr of nickel and 5600 MT/yr of cobalt. It will also include a sulfuric acid plant. Coming on the heels of the Ambatovy project is the Long Harbour Processing Plant in Newfoundland, Canada which will process the ore from Vale’s Voisey Bay mine in Labrador. Voisey’s Bay is expected to generate more than 50,000 MY/yr of nickel ore when it starts up in 2013. Overall, Vale S.A. is expected to spend more than $26 billion during the next two years to complete projects currently under construction.

Next up will be the Baja Mining’s Boleo project in Mexico on the Baja peninsula. When commissioned in 2013, the $US 858 Million Boleo project is expected to produce 60,000 MT/yr copper, 3100 MT/yr cobalt, 36,000 MT/yr zinc and 100,000 – 250,000 MT/yr manganese carbonate.

FRP Delivers Unmatched Value in Mineral Processing Environments

FRP based upon Derakane and Hetron epoxy vinyl ester resins has been used for decades to design corrosion resistant equipment for mineral processing environments. These materials routinely outperform stainless steel and rubber lined steel for both durability and cost. Moreover, the same global trends that are driving interest in nickel production are also driving up the price of stainless steel and higher nickel alloys. These specialty metals are often hard to come by resulting in long lead times for delivery. Rubber lined steel is a bit more affordable but requires continuing maintenance over time which ultimately drives up its cost considerably. Today, more and more design engineers and material specifiers are calling for FRP composites for equipment used in the refining and processing of a variety of metal ores.

Material costs obviously favor the use of FRP in the construction of mineral processing equipment. An even more compelling argument for their use, however, can be made when one examines their resistance to corrosion in aggressive hydrometallurgical environments. These processes often require materials of construction that can resist strong acids and high concentrations of acid chloride salts. FRP based on epoxy vinyl ester resin chemistry has the same chemical resistance to acid and better resistance to acid chloride salts than alloy C-276. Moreover, it is superior to 2205 stainless steel in both environments. In fact, depending on the environment, FRP can have a 20 year service life or longer.

Mineral Processing Applications

In metal extraction and refining processes, FRP is typically used for pipes, tanks, absorption towers, ductwork, solvent extraction vessels, and electrowinning cells. With the incorporation of the proper filler, FRP piping can provide remarkable durability and corrosion resistance in abrasive slurry piping. Tough Derakane and Hetron resins coupled with these unique fillers deliver exceptional abrasion resistance in the final product. Abrasion resistant FRP piping has proven to last longer and require considerably maintenance than rubber-lined steel.

Votorantim Metais, one of the ten largest zinc producers in the world recently invested US$ 500 million in their Cajamarquilla Refinery to increase production of refined zinc from 160 thousand to 320 thousand tons per year. The project included a sulfuric acid plant and acid plant scrubbers designed by Outotec and constructed by LEPSA S.A. A huge outlay of FRP tanks, scrubbers, piping and ducting was required for this extensive project. Outotec specified FRP made with Derakane epoxy vinyl ester resin for all of the FRP equipment due to its wide range of chemical resistance to acids, bases and organic compounds. FRP was found to withstand conditions that would require a considerably more expensive metal alloy.

The $US 4.3 billion Vale Inco Goro Nickel project on the South Pacific island of New Caledonia is another projects which has relied heavily upon FRP. More than 6000 MT of FRP went into the construction of this facility. Literally hundreds of storage tanks, scrubbers and processing vessels were specified to be fabricated with FRP based on Derakane epoxy vinyl ester resins along with miles and miles of abrasion resistant piping. The established durability of FRP in this demanding corrosive environment along with its inherent economics relative to specialty metals and rubber lined steel drove the decision to choose FRP for this immense project. Although environmental opposition and processing difficulties have delayed opening of the facility, it is expected to generate 60,000 metric tons of nickel and 5000 metric tons of cobalt annually when commissioned.

Summary

The operating conditions associated with mineral processing require materials of construction that can withstand process acids and acid chlorides at temperatures up to 90°C. This service is not compatible with most common metallic materials of construction. Only expensive metal alloys offer the corrosion resistance required. The use of fiberglass reinforced plastics based on Derakane and Hetron epoxy vinyl ester resins for the construction of electrowinning cells, storage and processing vessels, acid & abrasion resistant piping, ducting and acid plants offers durable and cost saving solutions for these applications. FRP has a distinct advantage over metal alloys and rubber-lined steel with lower installation costs, reduced maintenance and long service life proven with over 20 yrs of successful operating experience.

The case study was provide by Ashland Performance Materials.