In the iron industry, ferrous carbonate (FeCO3) is a valuable raw material because it can be reduced to elemental iron by hydrogen reduction. However, current industrial processes produce mixtures of FeCO3 and hematite (Fe2 O3) that are expensive, non-stoichiometric and sensitive to oxidation. This paper describes a new process for direct reduction of mineral iron carbonate with hydrogen in a CO2 rich environment, avoiding the formation of Fe2 O3. The result is a clean, low-cost and environmentally benign production route for iron and steel.
An x-ray diffraction spectrum of the product, exhibiting only the lines corresponding to the calcite structure of FeCO3, agreed well with the lines given on card 8-133 of the Powder Diffraction Standards Committee, Swarthmore, PA. The isomer shift of the hematite peaks also corresponded well to that reported in the literature.
Several investigations have been conducted to determine the bioavailability of supplemental iron from different sources in sheep. The results indicate that iron from ferrous carbonate is not as bioavailable as that from a more bioavailable source, such as ferrous sulfate. In addition, supplemental iron from ferrous carbonate is insufficiently efficacious for young animals that require an immediate response in hemoglobin synthesis.
A more recent investigation of the bioavailability of dietary iron from various sources in sheep was conducted using an ad libitum feeding experiment in which lambs were fed one of four treatments containing 0, 300, 600 or 1200 mg/kg diet of supplemental iron as ferrous carbonate. Supplemental iron increased copper, phosphorus and zinc utilization by the gastrointestinal tract but not magnesium or sulfur. It also increased iron concentrations in liver, spleen and bone but not in kidney and muscle.