The capillary viscometer is often used for viscosity measurement. However

in measuring of viscosity of settling suspensions

the suspensions must he agitated rather vigorously before entering the capillary to get a uniform concentration of slurry. The viscosity thus measured is always in error. A correction term has been introduced in this work to account for the velocity head due to agitation. Viscosities of ammonia solutions and slurries of laterite ore and ammonia solution were determined satisfactorily with correction term mentioned above. The effect of temperature and solid concentration on viscosity was studied. Results indicate that the laterite ore slurry with volume concentration of solid particles less than 8.45% can be considered as Newtonian fluid. The relationship between its viscocity and volume concentration can be expressed by Vand equation: μ/μ0=exp(bcv).