Impurities from phosphogypsum had deleterious effect on the property of cement when used as cementretarder, which caused limited application.
磷石膏用作水泥缓凝剂时，其中含有的杂质对水泥的性能产生不利影响，因此使其应用受到限制。
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The paper introduces the field performance of a new kind of oil well cementretarder QR-300C, and its application in production string cementing on three deep exploratory Wells at Tuha oil field.