Iron(II) sulfate was used in the textile industry for centuries as a dye fixative. It is used historically to blacken leather and as a constituent of ink. The preparation of sulfuric acid ('oil of vitriol') by the distillation of green vitriol (Iron(II) sulfate) has been known for at least 700 years. Together with other iron compounds, ferrous sulfate is used to fortify foods and to treat and prevent iron deficiency anemia. Constipation is a frequent and uncomfortable side effect associated with the administration of oral iron supplements. Stool softeners often are prescribed to prevent constipation. Ferrous sulfate was used in the manufacture
History of the petroleum industry in Canada (oil sands and heavy oil) difficulties marketing its oil, the provincial government established a policy that would limit oil sands production. According to this policy, synthetic oil from the oil sands could supplement conventional oil sales, but could not displace it. Oil from the plant could not exceed 5 per cent of total volumes in markets already supplied by conventional Alberta oil. Financial difficulties delayed construction of the GCOS plant until a new investor - Sun Oil Company's Canadian subsidiary, today known as Suncor - was found. The capacity of the proposed plant increased to 7,500 cubic metres per day and the cost escalated from