What are the relevant parameters and meanings of mining steel strands?

In the field of mining engineering, the performance of mining steel strands is directly linked to the safety and stability of the project. Therefore, if the right steel strands are selected, the project safety will be firmly guaranteed, and the safety factor can be increased several times. Next, we will analyze the key technical parameters and meanings of mining steel strands for you to know them clearly.

1. Diverse materials, suitable for different working conditions

(1) High carbon steel (such as 82B): This is a high-quality high-carbon steel material with a carbon content of about 0.8%. High carbon steel has excellent strength and hardness. After special processing, it can give steel strands a strong bearing capacity. It is often used in mining scenes with high strength requirements, dry working environment and low corrosion risk.

(2) Galvanized steel: An effective protective barrier is formed by evenly coating a layer of zinc on the surface of the steel. The zinc layer can isolate air and moisture, prevent steel from rusting and corroding, and extend the service life of the steel strand. Galvanized steel strands are suitable for mine environments with high humidity, can resist a certain degree of oxidation and corrosion, and ensure that they can still function stably under humid conditions.

(3) Epoxy coated steel (anti-corrosion type): Epoxy resin coating is applied on the surface of steel. It is a high-performance anti-corrosion coating with excellent chemical corrosion resistance. Even in highly corrosive environments such as acidic mines, epoxy coated steel strands can rely on their strong coating to prevent acidic substances from corroding steel and ensure the structural integrity and mechanical properties of the steel strands.

2. Multiple diameters to meet the needs of project scale

(1) Common specifications include 15.2mm, 17.8mm, 21.6mm, 15.2mm, etc. Steel strands of various specifications are widely used in the support and reinforcement projects of various small and medium-sized mine tunnels; 17.8mm steel strands play a role in the support of some tunnels or small mines with high requirements for bearing capacity and large spans; 21.6mm steel strands are suitable for the support of the main tunnels and key mines of large mines with their stronger bearing capacity, and can withstand greater pressure and tension.

(2) The specifications of steel strands for super-large projects can reach 28.6mm: For some super-large mining projects with large scale, deep mining depth and complex geological conditions, 28.6mm super-large diameter steel strands become the first choice. With its sturdy structure and strong mechanical properties, this kind of steel strand can withstand huge rock pressure and complex stress changes, providing a solid guarantee for the safety and stability of super-large mining projects.

3. Tensile strength, key mechanical indicators

(1) The national standard GB/T5224 stipulates that the first-level steel strand is ≥1860MPa: This means that the cross-sectional area of the first-level steel strand per square millimeter can withstand at least 1860 MPa of tension. Such a high tensile strength enables the steel strand to effectively resist the tension and deformation of rocks in mining projects, prevent the support structure from failing due to excessive force, and ensure the stability of mine tunnels and mining sites.

(2) Ultra-high strength type can reach 2160MPa: With a tensile strength of 2160MPa, the ultra-high strength steel strand can still maintain good mechanical properties under extreme stress conditions. In deep mining and mining environments with high ground stress, this ultra-high strength steel strand can withstand greater tension, providing more reliable protection for the safety of deep mining projects.

4. Elongation, an important guarantee for safety

Elongation ≥3.5% is an important indicator of mining steel strand. This means that when the steel strand is subjected to tension, it can undergo elastic deformation within a certain range without breaking. In the mining process, there will be sudden rock movement, impact and other situations. At this time, the elongation of the steel strand can play a key role. It can buffer energy through its own deformation, avoid sudden breakage due to instantaneous force, provide important buffer for mining projects, and effectively reduce the probability of accidents.

5. Anti-corrosion level to cope with harsh environments

(1) AAA-grade galvanized layer (zinc layer ≥ 300g/m²): Steel strands with AAA-grade galvanized layer have no less than 300 grams of zinc attached to each square meter of steel surface. This thick zinc layer can provide long-term and effective anti-corrosion protection for steel strands. Even if used for a long time in a humid mine environment, it can effectively prevent steel from rusting, ensure that the strength and performance of the steel strands are not affected, extend the service life of the steel strands, and reduce maintenance costs.

(2) Epoxy resin coating: Epoxy resin coating has excellent chemical corrosion resistance and adhesion. In a humid and acidic mine environment, the epoxy resin coating can adhere tightly to the surface of the steel to form a solid protective film to prevent erosion by moisture, acidic substances, etc., ensuring that the steel strands can still work safely and reliably in harsh chemical environments.

6. Breaking force, intuitive bearing capacity

Take 15.2mm steel strand as an example, the breaking force of a single strand is ≥260kN (about 26 tons). This means that under ideal conditions, to break this 15.2mm steel strand, at least 260 kN of tension is required, which is equivalent to about 26 tons of weight. Breaking force is an intuitive indicator of the bearing capacity of steel strands. In the design and construction of mining projects, engineers will select steel strands with appropriate breaking force according to the actual stress conditions and safety factor requirements to ensure that the engineering structure can operate safely and stably under various working conditions.