Behaviours of Gairome-Clay Slurries at Constant Pressure Filtration

In the papers previously published by several other authors5), 7), the average specific resistance ofcakeatconstant pressure filtration, αf, was represented as a function of a single variable, that is, the filtration pressure p0. According to the results of our constant-pressure-filtration experiments with the so-called ceramic slurries, the ignition-plug slurry was the only case where αf was a function of a single variable p0, and αf of all other slurries was not so simple. In this paper we report the various filtration characteristics of Gairome-Clay slurries.Summaries of the results were as follows:i) ε vs. ps data obtained from the compression measurements by using a consolidometer are plott- ed in Fig. 1. (ε) was a function of ps only, and was not influenced by the slurry concentrations. (k·S02)vs. ε data from permeability measurements are plotted semilogarithmically in Fig. 2, resulting in approximate empirical equations (2). m-values predicted by equation (3) were found to be a function of p0 only, as shown in Fig. 3, and αapp-values predicted by equation (4) to be a function of s as well as of p0.ii) (Δθ/ΔV)vs. V relation at constant-pressure filtration with Gairome-Clay slurry, indicated a curve, which approached asymptotically to a straight line as V increased.iii) The relation of (K·S20)app·s vs. s, of each constant-pressure filtration, showed also a curve.iv) Applying the predicted m-values to the constant-pressure filtration results, the following empirical equations of αf were obtained.whereaad (dimensionless)Therefore, the average specific resistance, αf, of the Gairome-Clay cake at constant pressure filt- ration could be represented as the sum of the term (αapp) -including variables p0 and s only-, and the correction term (αcorr) -including variables p0, s and V.The term (αcorr) in the empirical equation of αf indicates the influence of degree of particle flocculation, depending on the slurry concentrations; while the term (αapp) in the expression of αf shows the occurrence of cake disflocculation due to the filtrate flow, in other words, the existence of a kind of scouring effect.