preliminary engineeringとは 意味・読み方・使い方

To inexpensively recover metal iron from decarburization refining slag and preliminary dephosphorized slag which are produced in a steelmaking process and utilize the steelmaking slag as a civil engineering and construction material or an environmental improvement material, which do not cause volume expansion and clouding phenomenon of seawater, and further as raw materials for phosphate fertilizers.例文帳に追加

製鋼プロセスで発生する脱炭精錬スラグ及び予備脱燐スラグから金属鉄を安価に回収するとともに、これら製鋼スラグを、体積膨張や海水の白濁現象を起こさない土木建築材料または環境改善材料、更には燐酸肥料用原料として利用する。 - 特許庁