A professional blasting material and an effective replacement in composite cement, concrete and mortar

Copper slag is one of the most appreciated blasting materials in Europe. It is an ecological and non-toxic product (free silica content <0.1%). It was first introduced in 1960 and since then it has been widely used to remove rust, old paint layers and contaminated layers on metal surfaces, stone, concrete, bricks, mainly in the metal, automotive, shipbuilding and petrochemical industries.

Until now, many studies have been conducted to determine the properties of copper slag in blasting operations. In order to determine the efficiency of copper slag as a blasting media, which means (1) the area cleaned per hour and (2) the consumption of abrasive for cleaning the reference surface, Kambham et al. conducted a study in 2005 at the New Orleans University, Department of Civil and Environmental Engineering. It is believed that the quality of the abrasive is an important factor in the blasting efficiency, in addition to other factors, such as (1) the blasting pressure – considered as 80, 100 and 120 PSI, and (2) the feed rate – 3, 4 and 5 revolutions of opening a reference Fina II valve. This study led to the following conclusions:

• Copper slag is a highly efficient blasting material, with excellent properties for cleaning and blasting various types of surfaces. As it is an ecological product, it can be successfully used for blasting in open spaces, with minimal impact on the environment. The possibility of reusing material ensures material savings for blasting indoors.
• The cleaned area is wider at 3 and 4 turns of the opening (for a Fina II reference valve). At 5 turns of the opening, the productivity decreases due to the turbulent flow of the material (the particles leaving the nozzle interact with the rebounding particles of the base surface, causing the particles to be broken down, leading to an increase in consumption).
• The abrasive consumption is optimal at a blasting pressure of 100 or 120 PSI when cleaning old paint layers, without registering significant variations in the case of rusted surfaces. At a blasting pressure of 80 PSI, the abrasive consumption is higher when removing old paint layers, due to the lower velocity effect (abrasive particles travel at a low velocity to the base surface).
• The blast pressure must be kept constant to avoid increasing consumption at low blast pressures and to avoid particle breakage at high blast pressures.

Copper slag is also used for the production of composite cements as a substitute for raw materials used in the production of clinker. Due to its high Fe content, copper slag acts as an iron-containing adjuvant in the production of clinker, while its low melting point can reduce the calcination temperature for cement clinker. At the international level, the clinker factor is about 75% in the industry, the remaining 25% is supplemented by copper slag and other materials, which provide excellent strength and durability properties to the composite cements. Concrete and mortar produced by replacing parts of river sand with copper slag are more resistant over time, have low permeability and low water absorption.

GritShells is a national leader in providing complete solutions for surface blasting, with a wide range of professional blasting materials. The company supplies large stocks of blasting materials, stored in optimal conditions, multiple grain sizes per material and fast delivery, both nationally and internationally.