Specific heat should be 40% that of water (4180 J/kg·K) and 60% that of Kaolin (780 to 950 J/kg·K), so 2140 to 2240 J/kg·K.

A text book on Differential Thermal Analysis may possibly help you. Good day!

I. Mixture rules for density and specific heat capacity of a suspension:

The following 'mixture rule' can allow us to estimate the specific heat capacity of the suspension (or slurry), Cp. having SI units J/(kg·K)), based at additive contributions of both the dispersed solid (S) particles (CpS) and of water (W) (or of solution or solvent; depending on dispersant phase), CpW: Cp ≈ (x·ρS·CpS + (1-x)·ρW·CpW)/ρ. Here, x denotes the volumetric fraction of dispersed solid; ρ, ρS, and ρW, stand for densities of suspension, dispersed solid, and dispersant phase, respectively.

Although smaller density tends to translate itself in higher heat capacity for the suspension, we must remind that both the quantities are interrelated because composition dependent.

The density of the suspension can also be estimated by a mixture rule, after the densities of dispersed solid and dispersant phase: ρ ≈ x·ρS + (1-x)·ρW. Thus we may alternatively write Cp ≈ (x·ρS·CpS + (1-x)·ρW·CpW) / [x·ρS + (1-x)·ρW], showing how the specific heat capacity of the suspension is expected to depend on the volumetric fraction of dispersed solid.

We may alternatively want to estimate the specific heat capacity of the suspension based on the mass fraction (w) of dispersed solid, rather than on the volumetric fraction, as above; then: Cp ≈ w·CpS + (1-w)·CpW.

II. For a derivation of Brongniart’s formula ─ often used for ceramic slurries ─ and of other formulas relating slurry density with concentration, you may check my answers to another question at this forum: https://www.researchgate.net/post/Can_anyone_suggest_a_smart_way_to_calculate_volume_fraction_of_a_solid_ferrofluid_in_a_solvent_or_solids_fraction

III. Mixture rule for the thermal diffusivity of a suspension:

Let k (W/(m·K)) be the thermal conductivity of the suspension, while α = k/(ρ·cp) is its thermal diffusivity. Accordingly, let kW be the thermal conductivity of water (W) (or of solution or solvent; depending on dispersant phase), and let kS be the thermal conductivity of the dispersed solid (S) particles. For the corresponding thermal diffusivity (m2/s), we have αS = kS/(ρS·cpS) for dispersed solid, and αW = kW/(ρW·cpW), for dispersant phase. Units for (1/α)3/2 are (s3/2/m3); for a convenient volumetric basis. We may hence reasonably adopt the following mixture rule to predict the thermal diffusivity of the suspension:

(1/α)3/2 = (1/αS)3/2·x + (1/αW)3/2·(1-x)

where x denotes the volumetric fraction of dispersed solid (VS/V).

Elsewhere at this forum, I have suggested a mixture rule to estimate the thermal diffusivity for a composite after those of its components: https://www.researchgate.net/post/Why-the-thermal-diffusivity-of-polymer-composites-increases-with-filler-loading

IV. About the temperature dependence of density, specific heat capacity, thermal conductivity, and thermal diffusivity, you may want to check my posts at:

https://www.researchgate.net/post/Is_the_thermal_diffusivity_of_a_material_temperature_dependent

Hi,

Hope these papers help you:

Experiment study on the thermal properties of paraffin/kaolin thermal energy storage form-stable phase change materials

Preparation, characterization and thermal properties of Lauryl alcohol/Kaolin as novel form-stable composite phase change material for thermal energy storage in …

Influences of impurities and mineralogical structure of different kaolin minerals on thermal properties of cordierite ceramics for high-temperature thermal storage