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Abstract

Studies1-4 have not only shown that metallic ion release occurs in vivo, but also presence of soluble and precipitated corrosion products, as well as metallic wear debris, in the liver, spleen, lungs, and even remote bone marrow of the iliac crest. Reports from these studies indicate that constant motion of the metal-on-metal prosthesis causes a wearing away of the passivated surface and an increase in metallic ion release. Research5 on the most important metal components used in orthopedic implant devices such as titanium reveals that they are considered due to possession of reliable mechanical performance as replacement for hard tissues, favorable properties of high rigidity, fracture toughness and strength. The research also identifies major examples of titanium implants used in orthopedics to include prosthetic hip and knee replacements for various types of spinal fusion instruments for stabilizing degenerate and unstable vertebral segments, fracture fixation devices of such as plates, screws and intramedullary rods as well as arthritis affecting these joints.Some orthopedics devices are made from stainless steel which is invariably a product of iron ore (concentrate) reduction and refining in the metallurgical industries, followed by addition of some alloying elements. Report 6 has shown that steel from which stainless steel is produced is chiefly made up of iron, carbon and also impurities such as sulfur, phosphorus etc. Research 7 has shown that application of stainless steel in biomedical engineering is restricted to temporary devices such as plates, screws, wires and fittings for orthopedics due to potential long term release of Cr 6+ , Cr 3+, and Ni 2+ into the body (Figure 1-4).Presence of high phosphorus concentration in iron (above admissible level) designated for production of engineering materials enhances embrittlement when these materials are placed to strive under service conditions. Phosphorus is very poisonous. Therefore, usage of iron with high phosphorus content for production of stainless steel used in the manufacture of orthopedic devices endangers the health of the patient. This culminates from risk of steel fracture (due to embrittleness) and phosphorus ion release into some body fluids. This formed the basis for several attempts already made to reduce the concentration of phosphorus inherent in iron oxide ores designated for production of engineering materials and orthopedic devices. Review of models and variables affecting phosphorus removal during processing of iron ores designated for production of orthopedics devices AbstractA review has been carried out to show models and variables affecting phosphorus removal during processing of iron ores (in acid solution) designated for production of orthopedics devices. Review of literatures show that the level of phosphorus removal during iron ore processing in acid solutions is largely dependent on the initial and / or final pH of the leaching solution. A decrease in the final solution pH is indicative of increased phosphorus removal and ...