Roadbed filling material with gold tailings

Abstract

The invention provides a roadbed filling material with gold tailings, which is characterized by comprising the following components in parts by weight: 10-40 parts of clay, 2-4 parts of lime and 54-88 parts of gold tailings. According to the method, the gold tailings can be used as filling materials, the tailings can replace natural sand, stone chips and filling materials, and the feasibility of the gold tailing road construction technology in actual engineering is determined.

Description

Technical Field

[0001] The invention relates to the technical field of road subgrade testing, in particular to a road subgrade filling material with gold tailings. Background Art

[0002] By the end of 2022, the output of gold mine tailings in my country has reached more than 1.5 billion tons, and the output is still increasing by 200 million tons each year. However, the comprehensive utilization rate of gold tailings is less than 20%, far lower than the average level of 60% in developed mining countries. The effective storage capacity of tailings ponds is also insufficient, and the comprehensive disposal of tailings is imminent. In order to solve the problem of comprehensive disposal of tailings, Dayuan Mining Area has carried out experimental research on the application of gold tailings in road subgrade. Summary of the invention

[0003] In view of this, the purpose of the present invention is to provide a roadbed filling material with gold tailings that can achieve the optimal replacement rate of gold tailings for natural sand, stone chips and filling materials, and determine the feasibility of gold tailings road construction technology in actual engineering.

[0004] The present invention is realized by the following method: a roadbed filling material with gold tailings comprises clay, gold tailings and lime, wherein the weight ratio is 10-40 parts of clay, 2-4 parts of lime and 54-88 parts of gold tailings.

[0005] Furthermore, the liquid and plastic limits, optimum moisture content, maximum dry density and bearing ratio of gold tailings as filling materials were studied.

[0006] The beneficial effects of the present invention are as follows: the present invention determines the optimal replacement rate of tailings for natural sand, stone chips and filling materials, and determines the feasibility of gold tailings road construction technology in actual engineering; the implementation of the project enables the full utilization of tailings, realizes the construction of tailings-free mines, and lays the foundation for promoting green mine construction and high-quality development; protects the natural environment, reduces the ground stacking of tailings, avoids air and water pollution in mining areas, and improves the ecological environment of mining areas; responds to the development plans of the country and the industry for green mining, and also has a positive impact on the local government's economic development plans and social development, and plays a positive role in promoting the modernization of my country's mining technology; adds a new way of tailings disposal, according to which 10 km of roads can be built each year, the road base thickness is 1.2 meters, the width is 10 meters, the tailings content is 56%, and the tailings specific gravity is 1.5 t / m 3 According to calculation, the tailings that can be comprehensively utilized each year are 10*1000*1.2*10*0.56*1.5=100,800 tons. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is the technical roadmap of the present invention.

[0008] Figure 2 Design table for modified gold tailings roadbed test.

[0009] Figure 3 This is a data table of the liquid and plastic limit test of gold tailings with different clay and lime content.

[0010] Figure 4 This is a table of gold tailings compaction test data with different clay and lime content.

[0011] Figure 5 This is a test data table of gold tailings bearing ratio with different clay and lime content. DETAILED DESCRIPTION

[0012] The present invention will be further described below in conjunction with the accompanying drawings.

[0013] See also Figure 1 As shown, the present invention provides an embodiment: a roadbed filling material with gold tailings, comprising clay, gold tailings and lime, with a weight ratio of 10-40 parts of clay, 2-4 parts of lime, and 54-88 parts of gold tailings; the liquid and plastic limits, optimum moisture content, maximum dry density and bearing ratio of gold tailings as filling materials are mainly studied, and the test methods and steps are formulated in accordance with the "Highway Geotechnical Test Code" (JTG 3430-2020), and the proportions and construction plans that can meet the "Highway Roadbed Design Code" (JTG-D30-2015) are found according to the test results of the liquid and plastic limits, optimum moisture content, maximum dry density and bearing ratio of gold tailings.

[0014] (1) Carry out mix design. This test is mainly designed to study the effect of clay and lime content on the physical properties of gold tailings as filling materials.

[0015] (2) Carry out tests on liquid limit, plastic limit, optimum moisture content, maximum dry density and bearing ratio according to the designed mix ratio.

[0016] (3) Analyze and process the measured data to determine the variation pattern and the admixture amount that meets the requirements of the roadbed specifications.

[0017] In order to determine the influence of clay content and lime content on the performance of gold tailings as roadbed filling materials, the relevant test regulations of the Highway Geotechnical Test Code (JTG 3430-2020) were referred to, and clay content (0%, 10%, 20%, 30%, 40%) and lime content (2%, 4%) were used as variables. Figure 2 As shown, specimens were prepared and tested to explore the improved liquid and plastic limit, optimum moisture content, maximum dry density and bearing ratio.

[0018] To explore whether the liquid and plastic limits of gold tailings mixed with clay and lime meet the "Highway Subgrade Design Specifications"

[0019] (JTG-D30-2015) requires that the liquid limit of roadbed filler should not be greater than 50% and the plasticity index should not be greater than 26. Therefore, the liquid and plastic limit tests were carried out on gold tailings with different amounts of clay and lime added.

[0020] analyze Figure 3 It can be seen that under the conditions of 2% lime content and 4% lime content, the liquid limit, plastic limit and plasticity index all increase with the increase of clay content.

[0021] Effective compaction of the roadbed is an important measure to ensure the stability and durability of the roadbed structure, and is also the key to ensuring the quality of the highway construction. Therefore, compaction tests were conducted on gold tailings with different amounts of clay and lime added. The dry density after compaction was calculated based on the dry density calculation formula.

[0022] analyze Figure 4 It can be seen that under the conditions of 2% lime and 4% lime, the optimum moisture content and maximum dry density increase with the increase of clay content.

[0023] The bearing ratio test is often used to test the ultimate bearing capacity of highway subgrade under unfavorable conditions and is one of the main parameters of pavement design. Therefore, a bearing ratio test was conducted on gold tailings with different amounts of clay and lime added.

[0024] Depend on Figure 5 It can be seen that under the conditions of 2% lime and 4% lime, when the clay content does not exceed 40%, the bearing ratio increases with the increase of clay content.

[0025] The above test starts from the application of gold tailings in roadbed, and explores the performance of gold tailings improved with different amounts of clay and lime as roadbed filling materials. Clay alone as roadbed filler has strong plasticity, is difficult to compact, and is easily unstable due to water erosion or scouring. The addition of clay to gold tailings can complement the deficiencies of the two materials. After mixing, it has an intercalation ability similar to sand, and the strength and stability are improved. When lime is added to the tailings, the lime undergoes a hydration reaction to generate Ca(OH)2 to produce Ca2+, which undergoes flocculation and ion exchange. The calcium ions in the lime are adsorbed to the surface of the gold tailings particles, displacing bound water, weakening the hydrophilicity and improving the water stability. The silica and alumina in the tailings react with the calcium from the lime to form hydrated calcium silicate (CSH) and hydrated calcium aluminate (CAH), which can form a gelled network structure and improve the bearing capacity of the roadbed.

[0026] When clay and lime are used to improve gold tailings, the liquid limit, plastic limit, plasticity index, optimum moisture content, maximum dry density, and bearing ratio all increase with the increase in the dosage. The combination of 40% clay and 4% lime can meet the bearing ratio requirements of urban expressways and trunk roads. Therefore, when clay and lime are used to improve gold tailings, the combination of 40% clay and 4% lime is recommended.

[0027] The modified gold tailings roadbed is constructed in the proportion of 56% gold tailings + 40% clay + 4% lime. The liquid and plastic limits, maximum dry density, optimum moisture content, bearing ratio, compaction degree and deflection are tested on the modified gold tailings roadbed. The relevant test values ​​can meet the requirements of relevant national standards.

[0028] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. A roadbed filling material with gold tailings, characterized in that: The invention comprises clay, gold tailings and lime, wherein the weight ratio of the clay is 10-40 parts, the lime is 2-4 parts, and the gold tailings is 54-88 parts.

2. The roadbed filling material with gold tailings according to claim 1, characterized in that: The liquid and plastic limits, optimum moisture content, maximum dry density and bearing ratio of gold tailings as filling materials were studied.

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