Recommended citation:
Sknar Yu., Hrydnieva T., Sknar I., Butyrina T. Processing of Secondary Raw Materials for the Recovery of Valuable Components. Monograph. Primedia eLaunch, Boston, USA, 2026. 128 p.
| INTRODUCTION | 8 |
| 1. ANALYTICAL REVIEW OF METHODS FOR OBTAINING SILICON (IV) OXIDE | 9 |
| 1.1.Physicochemical properties of silicon(IV) oxide | 9 |
| 1.1.1 Fields of application of silicon(IV) oxide | 9 |
| 1.1.2 Types, modifications and properties of silicon(IV) oxide | 10 |
| 1.1.3 Laboratory methods for obtaining silicon (IV) oxide | 12 |
| 1.2 Industrial methods for obtaining silicon(IV) oxide | 13 |
| 1.3 Methods for obtaining silicon (IV) oxide from various raw materials | 16 |
| 1.3.1 Methods for obtaining silicon (IV) oxide from soluble silicates | 16 |
| 1.3.2 Methods for obtaining silicon (IV) oxide from fluoride solutions | 17 |
| 1.3.3 Methods of silicon (IV) oxide precipitation | 18 |
| 1.3.4 Methods for obtaining silicon (IV) oxide from silicon tetrachloride… | 19 |
| 1.4 Rice husk – raw material for silicon(IV) oxide production | 20 |
| 2. CHARACTERISTICS OF RAW MATERIALS AND RESEARCH METHODS | 25 |
| 2.1 Use of rice production waste to obtain silicon (IV) oxide | 25 |
| 2.2. Physicochemical properties of rice husk and its components | 27 |
| 2.3 Theoretical and experimental methods for studying the properties of raw materials and obtained silicon (IV) oxide powders | 29 |
| 3. THERMODYNAMIC ANALYSIS OF THE PROCESS OF OBTAINING SILICA (IV) OXIDE FROM THE RICE HUSK | 31 |
| 3.1 Calculation Method | 32 |
| 3.2 Thermodynamic studies of the process of obtaining silicon (IV) oxide from the initial rice husk | 37 |
| 3.2.1 Thermodynamic analysis of the process of obtaining silicon (IV) oxide by pyrolysis from the initial rice husk | 37 |
| 3.2.2 Thermodynamic analysis of the process of obtaining silicon (IV) oxide from the initial rice husk in a water vapor environment | 40 |
| 4. INCREASING THE CONTENT OF AMORPHOUS SILICON(IV) OXIDE IN SOLID RICE HUSK RESIDUE BY PHYSICO-CHEMICAL METHODS | 51 |
| 4.1 Mechanism of the process of extracting a component of a solid particle by a liquid extractant | 51 |
| 4.2 Research on the chemical preparation processes of rice husk | 56 |
| 4.2.1 Lignin extraction process | 58 |
| 4.2.2 Cellulose extraction process | 68 |
| 4.2.3 Study of the cellulose extraction process after preliminary lignin removal (double treatment) | 72 |
| 4.2.4 Assessment of the accuracy of the accepted hypothesis about the mechanism of the studied processes of extraction of carbon-containing compounds | 74 |
| 5. THERMAL DECOMPOSITION OF SOLID RESIDUES FOLLOWING EXTRACTION FOR THE PREPARATION OF HIGH-PURITY SILICON (IV) OXIDE | 82 |
| 5.1. Methodology for Determining the Kinetic Parameters of the Thermal Decomposition Process of Solid Residues after Extraction | 82 |
| 5.2. Investigation of the Kinetics of the Thermal Decomposition of Solid Residues after Extraction for the Production of Silicon (IV) Oxide | 86 |
| 5.2.1. Investigation of the Kinetics of the Thermal Decomposition of Solid Residues after Lignin Extraction | 86 |
| 5.2.2 Study of the kinetics of the thermal decomposition process of solid residues after two-stage extraction to obtain silicon (IV) oxide | 96 |
| 5.3 Study of thermal treatment processes of solid residues after extraction to obtain amorphous silicon (IV) oxide | 104 |
| 5.3.1 Study of the chemical composition of rice husk and solid residues after extraction to obtain amorphous silicon (IV) oxide | 104 |
| 5.3.2 Thermal treatment of solid residues after extraction to obtain amorphous silicon(IV) oxide | 110 |
| 5.4. Investigation of the dispersion composition and basic properties of amorphous silicon (IV) oxide | 114 |
| CONCLUSIONS | 120 |
| REFERENCES | 123 |