Detailed Interpretation of Production Stages: Ensuring Efficient Operation of Tanzania Gold Plant

 The Tanzania 1,200t/d gold mineral processing plant, as a large-scale EPC+M+O project undertaken by Xinhai, has a complete and scientific production process, which is divided into four core stages: crushing, grinding and classification, separation (all-slime cyanidation), and tailings treatment. Each stage is closely connected and mutually supportive, forming a complete production system. The rational design and strict control of each production stage are the key to ensuring the plant’s 1,200t/d production capacity, high leaching rate and stable operation. This article will interpret each production stage in detail, showing Xinhai’s professional design and refined management in the project.

The crushing stage is the first link of the entire mineral processing process, responsible for breaking large raw ore into small particles that meet the requirements of the grinding stage. The Tanzania project adopts an open-circuit crushing process, which is a scientific choice based on the characteristics of the raw ore and the project’s production scale. The raw ore mined from the mine has a large particle size, generally up to several meters, which cannot be directly entered into the mill for grinding. The open-circuit crushing process is composed of multiple crushers, which break the raw ore step by step from coarse to fine.

In the crushing stage, Xinhai selected advanced and efficient crushing equipment according to the hardness and particle size of the raw ore, ensuring the crushing efficiency and product quality. The first stage of crushing uses a jaw crusher to break large raw ore into coarse ore with a particle size of less than 300mm; the second stage uses a cone crusher to further crush the coarse ore into medium ore with a particle size of less than 50mm; the third stage uses a impact crusher to crush the medium ore into fine ore with a particle size of less than 10mm, which meets the feeding requirements of the grinding stage. The open-circuit crushing process has the advantages of simple flow, high crushing efficiency and low energy consumption, which is very suitable for large-scale production. At the same time, Xinhai equipped the crushing workshop with professional dust removal equipment to reduce dust pollution and meet the local environmental protection requirements.

The grinding and classification stage is the core link to realize the dissociation of gold particles, which directly affects the subsequent leaching effect. The Tanzania project adopts a one-stage closed-circuit grinding and cyclone classification process, which is an advanced grinding and classification mode in the current mineral processing industry. The closed-circuit grinding means that the ore after grinding is sent to the cyclone for classification, and the unqualified coarse-grained ore is returned to the mill for regrinding, while the qualified fine-grained ore enters the subsequent cyanidation leaching stage. This cycle ensures that the grinding product has a uniform particle size and sufficient dissociation of gold particles.

Xinhai selected a large-scale energy-saving ball mill for the grinding stage, which has the advantages of high grinding efficiency, low energy consumption and stable operation, and can meet the grinding demand of 1,200t/d ore. The cyclone used in the classification stage has the characteristics of high classification efficiency and accurate classification, which can effectively separate coarse and fine ore particles. The technical team of Xinhai optimized the matching parameters of the mill and cyclone through experiments, determined the optimal grinding concentration and classification efficiency, and ensured that the particle size of the grinding product reaches -200 mesh accounting for more than 85%, laying a solid foundation for the subsequent all-slime cyanidation leaching.

The separation stage adopts the all-slime cyanidation process, which is the core link of gold extraction. The qualified ore pulp after grinding and classification is sent to the cyanidation leaching tank, and cyanide solution and lime are added to carry out the leaching reaction. The lime is used to adjust the pH value of the pulp to prevent the cyanide from being decomposed and improve the leaching effect. During the leaching process, the aeration device continuously aerates the pulp to promote the reaction between gold particles and cyanide solution, so that the gold is dissolved into the solution to form gold cyanide complex.

After the cyanidation leaching, the gold-bearing solution is adsorbed by activated carbon to obtain gold-bearing carbon, which then enters the desorption electrolysis system. The desorption electrolysis system uses high temperature and high pressure to desorb the gold from the activated carbon, and then obtains gold mud through electrolysis. The gold mud is smelted to obtain finished gold. The tailings after cyanidation leaching are sent to the thickening and dewatering system for solid-liquid separation. The separated clear water is recycled to the production system for reuse, and the dewatered tailings are stacked in the tailings yard, realizing the harmless treatment and resource utilization of tailings.

Each production stage of the Tanzania 1,200t/d gold plant is designed and managed in a refined way, which ensures the efficient and stable operation of the plant. The close connection between the stages and the optimized process parameters make the plant’s production capacity and leaching rate reach the design requirements, providing a reliable guarantee for the project’s economic benefits. Xinhai’s professional technical strength and refined management level are fully reflected in each production stage, setting a good example for the construction of similar gold processing plants in East Africa.

All-Slime Cyanidation Process for Tanzania 1,200t/d Gold Plant

 The choice of mineral processing process is the key to determining the gold recovery rate and production efficiency of a gold processing plant, especially for the Tanzania 1,200t/d gold project with complex ore properties. The project involves two types of ore—sulfide ore with a high gold grade of 10.7g/t and oxide ore with a relatively low grade of 2.4g/t, and gold is the only valuable element. To efficiently recover gold from these two types of ore, Xinhai’s technical team经过 in-depth analysis of ore properties and a large number of experimental verifications, finally determined to adopt the all-slime cyanidation gold extraction process, which achieved excellent leaching effects—93.75% for sulfide ore and 91.58% for oxide ore, setting a high standard for gold recovery in the local area.

All-slime cyanidation is a mature and efficient gold extraction process, which is mainly suitable for processing fine-grained disseminated gold ore, oxide gold ore and sulfide gold ore after oxidation roasting. Its core principle is to fully dissociate gold particles from gangue minerals through fine grinding, and then use cyanide solution to leach gold, so as to realize the separation of gold from ore. For the Tanzania project, the all-slime cyanidation process is particularly suitable because of the fine embedded particle size of gold in both sulfide and oxide ores, which requires sufficient dissociation through grinding to ensure the leaching effect.

The reason why Xinhai chose the all-slime cyanidation process for the Tanzania project is not only based on the ore properties, but also considering the project’s production scale and economic benefits. Compared with other gold extraction processes such as gravity concentration-cyanidation combined process, the all-slime cyanidation process has the advantages of simple process flow, high gold recovery rate, stable operation and low production cost, which is very suitable for large-scale production of 1,200t/d. At the same time, the process can effectively handle both sulfide and oxide ores, avoiding the need to set up two sets of independent processing systems, which greatly reduces the project’s investment and operation cost.

To ensure the leaching effect of the all-slime cyanidation process, Xinhai made targeted optimizations in the key links of the process. First of all, in the grinding stage, a closed-circuit grinding and cyclone classification process was adopted to ensure that the ore is ground to the required particle size, so that the gold particles are fully dissociated. The particle size of the grinding product directly affects the leaching rate—if the particle size is too coarse, the gold particles cannot be fully contacted with the cyanide solution, resulting in low leaching rate; if the particle size is too fine, it will increase the viscosity of the pulp, affect the leaching efficiency and increase the energy consumption. Xinhai’s technical team determined the optimal grinding particle size through a large number of experiments, balancing the leaching effect and energy consumption.

Secondly, in the cyanidation leaching stage, Xinhai optimized the leaching parameters such as cyanide concentration, leaching time, pulp pH value and aeration rate. For sulfide ore with high gold grade, the leaching time was properly extended and the cyanide concentration was adjusted to ensure that the gold is fully leached; for oxide ore with low grade but easy leaching, the leaching parameters were optimized to improve the leaching efficiency and reduce the consumption of cyanide. At the same time, Xinhai adopted advanced leaching equipment to ensure the uniform mixing of pulp and cyanide solution, and improve the contact efficiency between gold particles and leaching agent.

The application of the all-slime cyanidation process in the Tanzania 1,200t/d gold project has achieved remarkable results. The leaching rate of sulfide ore reached 93.75% and that of oxide ore reached 91.58%, which are higher than the average level of the same type of gold projects. This not only ensures the full utilization of gold resources, but also brings considerable economic benefits to the customer. In addition, the all-slime cyanidation process adopted by Xinhai has good environmental protection performance—through the effective treatment of cyanide-containing wastewater and tailings, the environmental pollution caused by the production process is minimized, which meets Tanzania’s strict environmental protection requirements.

The successful application of the all-slime cyanidation process in the Tanzania project fully demonstrates Xinhai’s strong technical strength and ability to customize solutions according to ore properties. This process not only provides a reliable technical guarantee for the project’s stable operation and high efficiency, but also provides a valuable reference for the processing of similar gold ores in East Africa. In the future, Xinhai will continue to carry out technological innovation, optimize mineral processing processes, and provide more efficient and environmentally friendly technical solutions for global mining customers.

Tanzania 1,200t/d Gold Mineral Processing Plant: Xinhai’s EPC+M+O Success and Technological Innovation

 Tanzania, a country rich in gold resources in East Africa, has become a key market for global mining investment with its abundant mineral reserves and improving investment environment. Against this backdrop, Xinhai Mining, a leading provider of mineral processing complete solutions, successfully undertook the Tanzania 1,200t/d gold mineral processing plant project, an integrated EPC+M+O project that integrates Engineering, Procurement, Construction, Mining Management and Operation. This project, with its unique ore properties and high production scale, has become a benchmark for efficient and sustainable gold mining in Tanzania, demonstrating Xinhai’s strong comprehensive strength in the global mining service field.

The Tanzania 1,200t/d gold project is distinctive in its ore composition: it consists of sulfide ore with a gold grade of 10.7g/t and oxide ore with a gold grade of 2.4g/t, with gold as the only valuable element. This ore characteristics put forward special requirements for the mineral processing process—how to efficiently recover gold from two types of ore with very different grades and properties, while ensuring the stability of production capacity and economic benefits, has become the core challenge of the project. Xinhai, relying on its years of experience in gold mineral processing and rich overseas project practice, customized a targeted overall solution for the project, and the EPC+M+O service mode adopted in the project has laid a solid foundation for the smooth implementation and long-term operation of the project.

The EPC+M+O mode adopted in this project is an advanced service mode in the current large-scale mineral processing plant construction, which solves the pain points of customers in coordinating multiple links such as design, construction and operation. For the Tanzania project, Xinhai took full responsibility for the whole process from the initial project research, process design, equipment procurement and manufacturing, on-site construction and installation, to the later equipment commissioning, trial operation, operation management and technical support. This integrated service mode not only reduces the communication cost and project risk for customers, but also ensures the consistency and efficiency of the whole project process, enabling the project to be put into production on schedule and achieve expected benefits.

In the early stage of the project, Xinhai’s professional technical team conducted in-depth on-site investigations in Tanzania, fully understanding the local natural environment, transportation conditions, industrial supporting facilities and relevant mining policies and regulations. Tanzania has strict requirements on environmental protection and production safety in the mining industry, and Xinhai integrated environmental protection and safety concepts into every link of project design and construction. In view of the local water and electricity resources and labor conditions, Xinhai optimized the process design and equipment configuration to adapt to the local actual situation, reducing the project’s operation cost and improving the adaptability of the plant.

In the process of project implementation, Xinhai adhered to the principles of high quality, high efficiency and safety, and strictly controlled every link. The professional construction team and installation team sent by Xinhai have rich overseas project experience, and strictly constructed and installed in accordance with the design drawings and international standards, ensuring the construction quality. At the same time, Xinhai established a special project management team to track the project progress in real time, coordinate the cooperation between various teams, and solve the problems encountered in the construction process in a timely manner, ensuring the smooth progress of the project.

After the completion of the project, Xinhai continued to provide operation management and technical support services. The professional operation management team formulated scientific operation plans, optimized process parameters, and ensured the stable operation of the plant. The technical support team provided regular technical training and on-site guidance for the local operation personnel, helping them master the operation skills of equipment and process, and realizing the independent operation and management of the plant by the customer. Up to now, the Tanzania 1,200t/d gold processing plant has been operating stably, with the leaching rate of sulfide ore and oxide ore reaching 93.75% and 91.58% respectively, which has been highly recognized by the customer.

This project is not only a successful practice of Xinhai’s EPC+M+O mode in East Africa, but also a positive contribution to the development of Tanzania’s mining industry. It has introduced advanced mineral processing technology and management experience to Tanzania, promoted the technological progress of the local mining industry, created a large number of local employment opportunities, and driven the development of related industries. In the future, Xinhai will continue to uphold the concept of technological innovation and sustainable development, and provide more high-quality mineral processing solutions for global mining customers, helping more mining projects achieve efficient and green development.

Selection and Combination of Siderite Beneficiation Processes – Maximizing Resource Value

 Siderite beneficiation is a complex system engineering, and the selection of beneficiation processes is not fixed—it needs to be determined according to the specific characteristics of the ore, including particle size distribution, chemical composition, mineral intergrowth relationship, impurity content, and other factors. As mentioned earlier, the four core beneficiation processes (flotation, gravity separation, magnetic separation, magnetization roasting-weak magnetic separation) each have their own advantages and limitations. In practical industrial production, a single beneficiation process is often difficult to meet the requirements of high concentrate grade and high recovery rate. Therefore, the combination of multiple processes has become the mainstream trend of siderite beneficiation, which can give full play to the advantages of each process and maximize the utilization value of siderite resources.

First, let’s clarify the selection criteria of a single beneficiation process. For coarse-grained siderite ores (particle size 5-50mm) with simple composition and low impurity content, gravity separation (heavy-media separation or jigging separation) is the preferred method—it has large production capacity, low cost, and can effectively discard gangue. For fine-grained disseminated siderite ores (particle size less than 1mm) with complex intergrowth with gangue, flotation is more suitable—it can achieve effective separation of fine particles and improve the concentrate grade. For siderite ores with associated strong magnetic minerals (such as magnetite), magnetic separation (weak magnetic separation + strong magnetic separation) can be adopted to recover strong magnetic minerals first and then separate siderite. For difficult-to-beneficiate siderite ores (fine particle size, high impurity content, close intergrowth), the magnetization roasting-weak magnetic separation process is the most effective choice, which can fundamentally solve the problem of low separation efficiency.

On the basis of single process selection, the combination of multiple processes can further improve the beneficiation effect. The common combined processes for siderite include: gravity separation + flotation, magnetic separation + flotation, magnetization roasting-weak magnetic separation + flotation, etc. For example, in the processing of coarse to medium-grained siderite ores with fine-grained impurities, the "gravity separation + flotation" combined process is often adopted: first, gravity separation is used to recover coarse-grained siderite concentrate, and the tailings or intermediate products of gravity separation (which contain fine-grained siderite) are sent to flotation for re-selection, so as to improve the overall iron recovery rate and concentrate grade. Another example is the "magnetization roasting-weak magnetic separation + flotation" combined process for difficult-to-beneficiate siderite: after magnetization roasting and weak magnetic separation, the obtained concentrate may still contain a small amount of fine-grained gangue, which can be further purified by flotation to obtain high-grade iron concentrate (iron grade above 65%), meeting the requirements of the steel industry.

In addition to the selection and combination of processes, the optimization of process parameters is also crucial to improving beneficiation efficiency. For example, in the flotation process, the optimization of pulp pH, reagent dosage, and flotation time can significantly improve the separation effect; in the magnetization roasting process, the control of roasting temperature, reducing agent dosage, and roasting time directly affects the transformation rate of siderite to magnetite; in the gravity separation process, the adjustment of separation medium specific gravity and water flow velocity can improve the separation accuracy.

In conclusion, the selection and combination of siderite beneficiation processes must be based on detailed ore characterization and experimental research, and the principle of "adapting to ore properties, optimizing process flow, reducing cost, and protecting the environment" must be adhered to. With the continuous development of mineral processing technology, new processes and equipment (such as high-efficiency flotation reagents, advanced magnetic separation equipment, and energy-saving roasting technology) are constantly emerging, which will further promote the efficient utilization of siderite resources and provide strong support for the sustainable development of the steel industry.

Siderite Magnetization Roasting-Weak Magnetic Separation Process – Solving the Difficulty of Beneficiation

 For siderite ores with complex compositions, fine particle size, and close intergrowth with gangue minerals, single beneficiation processes (such as flotation, gravity separation, or magnetic separation) often struggle to obtain high-grade iron concentrates. At this time, the magnetization roasting-weak magnetic separation process becomes the most effective solution. This process combines roasting and magnetic separation, transforming siderite into a strong magnetic mineral through roasting, thereby realizing efficient separation with conventional weak magnetic separation equipment. It is known as the "key technology" for difficult-to-beneficiate siderite and has been widely promoted and applied in industrial production.

The core of the magnetization roasting-weak magnetic separation process is the magnetization roasting step, whose principle is to heat siderite in a reducing atmosphere (using coal, coke, natural gas, or other reducing agents) to decompose the carbonate in the ore and transform siderite into magnetite (Fe₃O₄), a strong magnetic mineral. The chemical reaction equation is: 3FeCO₃ + C → Fe₃O₄ + 3CO₂↑ + CO↑. During the roasting process, two key changes occur: first, the carbon dioxide in siderite is decomposed and discharged, which increases the iron content of the ore (theoretical iron content of magnetite is 72.4%, which is much higher than that of siderite); second, the magnetic susceptibility of iron minerals is significantly enhanced—magnetite is a strong magnetic mineral, whose magnetic susceptibility is dozens of times higher than that of siderite, making it easy to be separated by weak magnetic separation. At the same time, the magnetic properties of gangue minerals (such as quartz, calcite) remain basically unchanged, which further improves the separation effect.

The magnetization roasting process is mainly divided into three types: shaft furnace roasting, rotary kiln roasting, and fluidized bed roasting. Among them, rotary kiln roasting is the most widely used in siderite beneficiation due to its stable roasting effect, large processing capacity, and strong adaptability to ore particle size. The rotary kiln is a long cylindrical equipment that rotates continuously; the ore and reducing agent are fed into the kiln from one end, and heated to 550-700℃ (the optimal roasting temperature for siderite) by a burner at the other end. Under the action of high temperature and reducing atmosphere, siderite is gradually transformed into magnetite. After roasting, the ore (called roasted ore) is cooled to the appropriate temperature and then sent to the next process.

The roasted ore is sent to a weak magnetic separator for separation. Due to the strong magnetic properties of magnetite, it is easily adsorbed by the magnetic field of the weak magnetic separator and separated from non-magnetic gangue to form high-grade iron concentrate. The weak magnetic separation equipment used is mainly a drum magnetic separator, which has the advantages of simple structure, high processing efficiency, and low energy consumption. Compared with strong magnetic separation, weak magnetic separation has lower equipment investment and operation cost, which greatly reduces the overall cost of the beneficiation process.

The magnetization roasting-weak magnetic separation process has the advantages of high iron concentrate grade, high recovery rate, and strong adaptability to difficult-to-beneficiate siderite ores. However, it also has certain limitations: the roasting process requires a large amount of energy and reducing agents, which increases the production cost; at the same time, the roasting process will generate flue gas, which needs to be treated to meet environmental protection standards. Therefore, in industrial design, it is necessary to comprehensively consider the ore properties, economic benefits, and environmental protection requirements to optimize the process parameters.