Effect of acidic treatment on rheological properties of Iraqi attapulgite clay

Abstract

Acidic treatment has a great influence on attapulgite clay rheological properties. The attapulgite characteristics such as purity, morphology and desperation of attapulgite clay are wholly controlled by acidic treatment. In this work, the purification of Iraqi attapulgite clay to be suitable in drilling fluid was investigated using acidic treatment. Three types of acid (acetic acid, citric acid and hydrochloric acid)with different concentrations((0.1869, 0.3064and0.4788) M citric acid,(0.5, 0.911 and 1) M hydrochloric acid,(0.911, 1.138 and 1.518)M acetic acid) were used. XRD and FE-SEM tests were utilized to study the attapulgite morphology while the rheological properties were tested using Ofite viscometer.The results show that the citric acid treatment had harmful influence on attapulgite morphology andled to serious reduction in its rheological properties.While; the use of hydrochloric acid had slighter impact than citric acid onattapulgite morphology. Therefore, the attapulgite rheological properties were better. In this work, the best result obtained by using acetic acid due to its ability to remove whole calcite mineral without causing any damageon attapulgite morphology. The yield of clay for purified attapulgite were(60.35,63.97,101.94) barrel/ton for attapulgite treated with(0.3064M) citric acid, (0.911M) hydrochloric acid and(1.138M) acetic acid respectively using distilled water; while, the yield of clay was (58.3,70.59,91.93) barrel/ton for same concentration of citric acid, hydrochloric acid and acetic acid respectively usingsalt water.