Feasibility study report of 500 tons wet sponge copper project

I. Background and basis of project nature and feasibility study

The project is the use of low grade copper oxide ore mining waste resources of all-Leaching - scrap iron replacement process to obtain copper sponge project.

Low-grade refractory copper oxide ore is difficult to mine using conventional conventional smelting processes. At present, a large number of experimental research and production practices on the properties of copper oxide ore and waste secondary scrap copper resources have been carried out at home and abroad. The production process of this oxidized ore and low grade ore and waste secondary scrap copper resources is treated by leaching-replacement process. It has the greatest advantage of low investment and low production cost, and can obtain better economic benefits and environmental and social benefits.

1.1 Project construction principles

Seriously implement the relevant national policies and regulations and the requirements of the higher authorities.

We will implement the "three wastes" governance "three simultaneous" approach, protect the environment, and improve labor hygiene conditions to meet national health standards.

In the general layout, it is necessary to save land when considering the land for engineering.

In order to save investment, this design makes full use of the existing cooperation conditions in the region, such as water supply, power supply, raw fuel and product transportation, machine repair, environmental monitoring, etc. This design does not consider the construction content and projects of this part.

The labor capacity of the production line is 4, and recruitment is carried out in the local area.

Second, the project's resource conditions

The raw materials are low-grade copper oxide ore, flotation tailings containing copper oxide ore, copper smelting furnace slag and the like. The main ingredients are (%):

Cu0.6-1.2% Fe28-30% S8.49% siO ₂ 28.8% CaO4.8%

Third, the company's production process selection

With the decreasing of copper sulfide ore resources, people pay more attention to the development and utilization of low-grade refractory copper oxide ore resources, and researched the “leaching-replacement” process to treat low-grade refractory copper oxide ore to produce sponge copper products. species hydrometallurgical process, with the production process is simple, using a closed circulation all liquid immersion, no production of waste discharge, this process has low investment cost, significant economic benefits, no environmental pollution, etc., for a small investment costs. The process flow is shown in Figure 1:

Figure 1 Sponge copper heap leaching process flow chart

Fourth, the main process production control conditions

(1) Leaching process

The heap leaching method will be used to crush the ore from the jaw crusher to a particle size of 4-8mm: heap leaching, using four sets of piles, supporting two sets of sump to collect the leaching solution, and configuring the acidity of 40-50g/l drip irrigation Dip.

Heaping operation conditions:

Reaction time: 50 days

Start acid (spray solution): 40-50g/l

Final acid (rich liquid): pH 1.5-2.0

Temperature: above 25 ° C

Average stack height: 3 m; bulk density: 1.5 T/ m ³

Ore size: 90%-10cm

Single stack area: 2000 m ²

Spraying speed: 5-10L/(m ² h) (including new pile 8.5; old pile 4.3)

Leaching type: two-stage countercurrent

Heap life: / day: 270

Copper leaching rate 65%

Leaching rich liquid ingredients:

Cu3-10g/l Fe5-10g/l Ni5-10mg/l

(2) Iron filing replacement process

The leachate is pumped from the leaching sump to the displacement tank, and the amount of iron filings is calculated based on the copper ion concentration of the leaching solution.

Operating conditions:

Starting acid: 8-10g/l; pH 1.5-2.0

Final acid: pH 2.0-2.5; 8-10 g/l

Temperature: 25 ° C

Starting copper concentration (before replacement) 3-10g/l

Final copper concentration (replacement final solution) 0.01-0.08g/l

The pump is used to pump the final liquid from the displacement tank for the old heap spray dripping, and the remaining precipitate is the final product sponge copper.

Five, metallurgical calculation

(1) Leaching process

A. The amount of spray liquid: According to the nature of the raw materials, the daily processing amount is 50 tons (dry), the average copper grade is 0.7%, in two piles (2000 m ² per pile); the spraying speed is 5-10L/( m ² h) meter: The total spray liquid required per hour is: 2000 × 2 × 8.5L = 34 m ³ .

B. Acid consumption: A(Kg/t)=22.3+6.8 (%CaCO ₃ ) where (%CaCO ₃ ) is the percentage of calcium carbonate, because the phase data of the mine is incomplete, the percentage of calcium carbonate It is estimated that 30% acid consumption is estimated to be 500 tons of sponge copper per year, and the average copper grade is 0.9%:

Total acid consumption of 500 tons of sponge copper = (22.3 + 6.8 × 30%) × 500 / 0.9% = 1690277 Kg = 1690t

The amount of iron scrap required for C and 500 tons of sponge copper = (56 × 500 t) / 64 = 437.5 t

Sixth, the main equipment calculation and selection

(1) heap leaching reservoir

The heap leaching tank requires two, one is a rich liquid pool with a volume of 500 m ³ ; the other is a lean liquid pool with a volume of 500 m ³ ; the above material is made of acid-resistant ceramic tile as the foundation, and the outer layer is made of 2 mm thick high-density polyethylene film.

(2) Leachate delivery system

An acid-resistant mortar pump is used. Conveying and spraying spray circulating fluid 40-50m ³ /h, requiring H=30m, Q=50m ³ /h pumping station; spray pipe network and conveying pipeline adopt flexible high-density polyethylene hose and equipped with mobile welding Equipment (plastic welding).

(3) Jaw Crusher

It needs to process 50 tons of ore per day, and the particle size needs to be broken to 3-8mm. It adopts 1-2 grade crushing and two-stage screening process. 1-2 jaw crushers are required.

(4) Replacement slot

The displacement tank volume is 500 m ³ ; the function of the stirring slurry device is set. The purpose is to accelerate the displacement reaction (the material is preferably 316L, other materials can be used but flexible high-density polyethylene is required to wrap 30mm acid resistance); if the displacement reaction is good, the moving scraper device can be omitted.

2, the main auxiliary materials

Concentrated sulfuric acid, iron filings.

Seven, a brief description of the production process

The copper oxide ore is crushed by a jaw crusher, and the crushed stone is transported by the loader to the leaching heap for leaching, and then the acidic immersion liquid is pumped for percolation leaching, and the leaching solution reacts with the ore, and the generated copper sulfate solution penetrates into the bottom layer by its own weight. It flows out from the drain pipe at the bottom of the ore layer, enters the sump, and is pumped to the displacement tank for replacement production. The heap leaching is the key in this process. The leaching rate is directly related to the success or failure of the process. When the pile is piled up, the bottom pad should be prepared in advance, and the vegetation of the heap leaching site should be removed first, and the ground should be leveled and compacted. The bottom pad is made of acid-resistant cement, and a 2mm thick high-density polyethylene film is laid on the outside. The heap leaching site is inclined to a certain angle to the sump, and a drainage ditch should be set up outside the yard to surround the heap, and the bottom pad is collected by liquid collecting. At the beginning, the ground is laid gradually from the ground to the high place, and 30-50 cm of sand which is not affected by acid is laid on the floor mat as a protective layer. After the pile is completed, a plastic pipeline is laid on the top for spraying the leachate, and the nozzles are arranged in an orderly arrangement with a distance of 3 meters and evenly distributed. The delivery is completed. That is, the start of the pile is carried out, and the leachate is sprayed onto the pile. The newly opened pair of leachate generally does not reach the requirement to be returned to the heap, and the four piles are countercurrently cycled until the desired concentration of the design is reached.

8. Environmental protection and labor safety, industrial hygiene

8.1 Environmental Protection

Wastewater: Due to the full wet leaching process, the process is a closed loop system. The water in this project is recycled. During the process of ore leaching, the water used for production and washing residual acid flows into the reserve liquid pool, which is used as supplementary water for production. Discharge, no industrial wastewater discharge, no pollution.

Waste residue: The production of leaching slag by slurry washing-pressure filtration, completely meets the requirements of clean and pollution-free, and is a high-quality raw material for construction and road construction. The output of waste in this project is ton/year.

Exhaust gas: This project adopts pure wet process and no waste gas is generated.

Noise: The equipment of this project is small, and the noise at the boundary of the plant is lower than the value specified in Class II Noise Standard for Industrial Enterprises.

9. Economic and social benefits

1. Construction investment estimate

The estimated investment of the feasibility study of this project is 20-600,000 yuan.

Among them, the civil engineering project is 50,000 yuan; the equipment and installation project is 300,000 yuan; the other expenses are 100,000 yuan.

2. Economic benefits

Unit consumption and cost of tons of copper

In summary, the project is very feasible with low investment, low risk, good efficiency and broad prospects.

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