# Complex Processing of Saponite Waste from a Diamond-Mining Enterprise
## 8 Kinetics  
The optimal calcium aluminosilicate dose (Figure 8) was investigated based on a sample of quarry water with a 3600 mg/dm\({}^{3}\) concentration of suspended particles. According to the obtained results, no noticeable sedimentation occurs with a low dose of inorganic coagulant. With a 0.3 g/dm\({}^{3}\) dose of calcium, aluminosilicate sedimentation begins and has average kinetics; with an increased dose up to 0.4 g/dm\({}^{3}\), it reaches a maximum. A further increase in the coagulant dose does not demonstrate any significant effect. Thus, the optimal dose is between 0.3 and 0.4 g/dm\({}^{3}\).  
Measurements of the condensed material density after 1 h of settling time of the saponite suspension showed that it is equal to 1.018 g/cm\({}^{3}\), which is not sufficient for dry storing. In order to increase the density of the condensed mineral, additional studies were conducted with nepheline concentrate and belite sludge as a weighting agent for condensed sediment [26; 27; 28]. According to the results of this research, it was found that the density of the condensed sediment and its cementation are much better with the belite sludge weighting agent. Belite sludge is a mixture of artificial minerals with the following composition, obtained by X-ray diffraction: belite (\(\beta\)-C2S) (d = 2.89, 2.74, 2.41 A), calcium hydosilicate (d = 3.38, 3.05 A), calcium hydosulfo aluminate (d = 2.19 A), calcium hydroxide (d = 2.62 A), calcite (d = 2.29 A), and unreactedalite (d = 2.79 A) [29]. The main component is belite (a phase of dicalcium silicate). The \(\beta\) modifications with imperfect crystallization and the \(\alpha^{\prime}\) modification have high hydraulic activity [8]. The results of the condensed sludge density measurements are presented in Table 4.  
Thus, in combination with an inorganic mineral reagent, applying the belite sludge significantly increases the deposition rate of the formed particles, removes further water from the interlayer space of clay minerals, and increases the density of the condensed product [30].  
The chemical composition of the condensed part permits waste-free production as shown in the CaO-Al\({}_{2}\)O\({}_{3}\)-SiO\({}_{2}\) diagram, replenishing the calcareous part of the coagulant and, thus again obtaining a reagent for the sedimentation and thickening of saponite pulp in the mining and processing plant (Table 5). The aluminosilicate obtained with calcium also has improved qualities for use in building materials and other kinds of secondary products. The production of building materials is a significant consumer of that kind of raw material and can make a significant contribution to recycling sludge from saponite waste treatment [31]. Cement composites make up the main share in the production of materials, so the involvement of secondary resources in their production is relevant [32; 33].  
\begin{table}
\begin{tabular}{c c c} \hline
**Seal Type** & **Amount of Clarified Water, mL** & **Density after 1 h, g/cm\({}^{3}\)** \\ \hline Without seal & 150 & 1.018 \\ \hline Belite sludge & 170 & 1.036 \\ \hline Nepheline concentrate & 120 & 1.029 \\ \hline \end{tabular}
\end{table}
Table 4: Results obtained after compaction of the thickened part.  
When traditional compounds (aluminum sulfuric acid, aluminum oxychloride, polyacrylamide flocculant) are used as coagulants, it becomes almost impossible to use the condensed minerals. The hazard class of the sediment is 4 after the thickening process with aluminum sulphate, oxychloride, and polyacrylamide flocculant. After coagulation, substances in the sediment lead to certain disruptions to the ecological system, but it is able to recover in about 3 years.