Local Raw Materials for Building Materials in the Oil- and Gas-Bearing Regions of Tomsk Oblast
Abstract Generated abstract
This paper evaluates the Koltogor deposit of low-melting loams near Strezhevoe as a local raw material source for construction in the oil- and gas-bearing northern districts of Tomsk Oblast, where imported materials limited industrial and housing development. It characterizes the loams by occurrence, grain-size and chemical composition, mineralogical features, plasticity, and laboratory and plant tests for brick and expanded-clay production. The authors find that the loams are suitable for producing building brick of grades 75 to 100 at 950 to 1000°C, and that their otherwise unstable bloating behavior can be improved with small additions of diesel oil or fuel oil. Plant trials indicate that, with petroleum-product additives and local fuel resources, the deposit could support mechanized local production of brick and class A expanded clay.
Full Text
Local Raw Materials for Construction Materials in the Oil- and Gas-Bearing Regions of Tomsk Oblast
P. G. Usov, N. F. Voronova
(Presented by the scientific seminar of the Department of Silicate Technology)
The development of the oil and gas fields of Tomsk Oblast is associated with extensive industrial and housing construction. Construction in the northern districts of the oblast, directly in the areas where oil and gas occur, is hindered by the fact that it is carried out using imported construction materials. The region being developed is, in industrial terms, virgin territory. The local construction-materials industry is almost completely absent there. The matter is further complicated by the fact that in this region deposits of nonmetallic raw materials for the construction-materials industry are not widespread. Therefore, each newly discovered deposit is of great value.
The Koltogor deposit of low-melting loams is located in the immediate vicinity of the settlement of Strezhevoe, on the right bank of the Ob River. The loams occur close to the ground surface, beneath a vegetative layer 0.2–0.3 m thick. In their natural state they have a brown, brownish-gray, and dark-gray color. The thickness of the loam bed is about 5 m. The loams contain no coarsely dispersed inclusions. Fractions larger than one mm are absent in them. In terms of the content of clay particles (fractions smaller than 5 μm), the loams belong to the middle group with the second class of plasticity.
The chemical compositions of the loams are given in Table 1. The clayey fraction
Table 1
Chemical compositions of loams
| Borehole No. | Sampling depth, m | LOI | SiO₂ | TiO₂ | Al₂O₃ | Fe₂O₃ | CaO | MgO | Total |
|---|---|---|---|---|---|---|---|---|---|
| 31-a | 0.1—3.8 | 8.48 | 62.32 | 0.86 | 16.46 | 6.38 | 2.13 | 2.97 | 99.60 |
| 31-b | 3.8—5.4 | 7.48 | 65.12 | 0.88 | 15.65 | 5.42 | 1.85 | 2.31 | 98.71 |
| 40-b | 2.5—5.5 | 6.54 | 66.72 | 0.86 | 14.66 | 5.18 | 2.11 | 2.66 | 98.73 |
| 45-a | 0.2—2.3 | 10.86 | 60.40 | 0.85 | 16.17 | 6.78 | 1.86 | 3.04 | 99.96 |
| 52-a | 0.1—2.5 | 10.00 | 61.94 | 0.86 | 16.48 | 5.90 | 1.83 | 2.62 | 99.63 |
of the loams (fractions smaller than 1.0 μm) has a montmorillonite composition and is described by the equation:
\[ 3\mathrm{H}_2\mathrm{O}\cdot \mathrm{Ca}_{0.19}(\mathrm{Al}_{1.6}\cdot \mathrm{Fe}_{0.3}\cdot \mathrm{Mg}_{0.1})_2\cdot \mathrm{Si}_4(\mathrm{O}_{9.8}\cdot \mathrm{OH}_{2.2})_{12} \]
The grain-size and chemical compositions of the rock are fairly consistent; their fluctuations fall within narrow limits. The loams contain no carbonate rocks. The loams are suitable for producing building brick. When processed plastically, they yield building brick of average grades “75–100.” The optimum firing temperature for the brick is 950–1000°C.
For northern regions, it is important to find raw material for producing a lightweight aggregate for concrete—expanded clay—whose use makes it possible to manufacture lightweight building structures with high thermal-insulation properties. The chemical compositions of the loams make it possible to assume that, in their natural state, they are low-quality raw material for the production of expanded clay. This was also confirmed by direct laboratory studies. Their bloating coefficient during firing is low and unstable. The bloating of loams during firing is improved by introducing organic gas-forming agents—diesel oil or fuel oil—into them. In this case, diesel oil or fuel oil promotes not only gas evolution during firing, but also the formation of readily fusible ferruginous silicates, which increase the mechanical strength of the expanded clay [1, 2]. The bloating temperature of the expanded clay is 1200°C. The bloating time is 7 minutes.
The bloating capacity of the loams of technological samples is given in Table 2.
Table 2
Bloating capacity of loams of technological samples
| Sample no. | Borehole no. | Sampling depth, m | Bloating coefficient in natural state | Bloating coefficient with addition of 2% diesel oil | Bulk density, g/cm³, in natural state | Bulk density, g/cm³, with addition of 2% diesel oil |
|---|---|---|---|---|---|---|
| 51 | 31-a | 0.1–3.8 | does not bloat | 2.59 | — | 0.56 |
| 52 | 31-b | 3.8–5.4 | 1.92 | 2.60 | 0.80 | 0.56 |
| 63 | 40-a | 0.1–2.5 | 2.33 | 2.46 | 0.65 | 0.58 |
| 64 | 40-b | 2.5–5.5 | 1.77 | 2.43 | 0.85 | 0.60 |
| 71 | 45-a | 0.2–2.3 | 2.53 | 2.64 | 0.60 | 0.55 |
| 83 | 52-a | 0.1–2.5 | 2.42 | 2.80 | 0.61 | 0.54 |
| 98 | 78-a | 0.1–2.4 | 2.66 | 3.66 | 0.55 | 0.35 |
With the addition of two percent diesel oil, the loams become suitable for producing expanded clay with a bulk density of about 0.54. At the same time, their bloating properties are well stabilized.
Tests of the suitability of the loams for producing expanded clay were carried out under plant conditions according to the following scheme: clay-receiving bunker—box feeder—belt conveyor—stone-separating rolls—clay mixer—processing slotted rolls—perforated press of grade S.M.-420—drying drum—storage bunker for dry granules—rotary kiln. The loam was tested with a natural moisture content of 19%. It was moistened additionally with dry steam. Fuel oil in the amount of one percent was fed to the belt press. The granules after the perforated press were not dusted. The moisture content of the granules after drying was about 15%. The grain-size composition of the dry granules was: fractions 10 to 20 mm—53%, 5 to 10 mm—30%, and 0 to 5 mm—17%.
The grain-size composition of the expanded clay after firing was: fractions 20 to 40 mm—18%, 10 to 20 mm—50%, 5 to 10 mm—24%, and 0 to 5 mm—8%. The bulk density and mechanical strength of the expanded clay by fractions are given in Table 3.
Table 3
Bulk density and mechanical strength of expanded clay by fractions
| Fraction, mm | Bulk density, kg/m³ | Strength readings on the instrument | Strength class |
|---|---|---|---|
| 0—5 | 600 | 28.63 | “A” |
| 5—10 | 496 | 34.06 | “A” |
| 10—20 | 489 | 27.09 | “A” |
| 20—40 | 486 | 27.47 | “A” |
| mixture | 475 | 25.15 | “A” |
On the basis of the strength index, loams with the addition of one percent fuel oil are suitable for producing class “A” expanded clay.
The loam deposit is located in an area where oil and gas occur. Using the latter as fuel, it is possible to establish local, highly mechanized production of building brick and expanded clay.
REFERENCES
- K. P. Azarov et al. Gas evolution and bloating of clay during firing of rocks. Building Materials, No. 4, 1963.
- S. M. Mikhailovich. The influence of petroleum products on the bloating of clayey rocks. Building Materials, No. 4, 1959.