Angola’s 50TPH Alluvial Diamond Washing Plant

Introducción

Diamond mining operations in Africa often face significant challenges when processing alluvial deposits, particularly those containing sticky clay and various-sized materials. In this case study, we explore how JXSC Mining Machinery successfully implemented a comprehensive 50TPH alluvial diamond washing plant in Angola, addressing the specific needs of the local mining operation and delivering impressive results.

 

The Challenge: Processing Clay-Rich Diamond Deposits

The client’s mine in Angola presented several processing challenges typical of African alluvial diamond operations:

• Raw ore consisting of alluvial diamond material with significant sticky clay content.
• Mixed material, including gravel and oversized stones.
• Required processing capacity of 50 tons per hour.
• Need to recover diamonds in the 2-30mm size range.
• Remote location with limited infrastructure.

These conditions demanded a robust solution that could effectively wash the clay-rich material, remove waste stone, and concentrate valuable diamonds while operating reliably in challenging conditions.

 

Custom-Designed Processing Flowchart

 

 

Explicación del diagrama de flujo

This plant is configured with a vibration feeder + trommel scrubber washing machine + belt conveyor + high frequency vibration screen + jig separator + water pumps

1. The customer can use a wheel loader or excavator to feed raw ore to the vibration feeder, the feeder is with 75mm gap. The feeder can remove the +75mm waste stone go to ground, need to spray water on the vibration feeder, so the 0-75mm slurry material will go to the trommel scrubber more smoothly. This vibration feeder is for removing oversize stone and feeds raw ore evenly to the trommel scrubber.

2.0-75 mm slurry go into lavador trómel for washing clean the raw ore, so the diamond can be released out from clay, it with two layer screen and mesh size 2mm &30mm, after washing in the drum, will screen out +30mm waste gravel, 2-30mm which contains diamond discharged from trommel scrubber will flow down to the high frequency vibration screen. At the same time, where is the 0-2mm slurry? This is muddy water that will flow into the sedimentation tank.

3. The high-frequency vibration screen has 18 mm and 8 mm PU screens, and with high-pressure water spray above the screen, so it can wash more cleanly the 2-30mm material. Then will get 2-8mm & 8-18mm two size range diamond material Which will be fed into two different jig machines.

Where is the 18-30mm bigger diamond? They will be transported to the stockpile by belt conveyor.

The belt conveyor here is designed with a variable speed motor, which can effectively control the speed of the belt conveyor, making it easier for manual selection of large diamonds.

4. The separador jig is for concentrate diamond. Here we use under-screen ore discharge, and can use iron ore and limonite as ore deposits.
2-8mm&8-18mm material will feed to two jig machine separatedly, so the concentration effect will be much better. The jig machine will get diamond concentrate ore.

If you need a higher purity diamond, you can select a single diamond manually or by X-RAY SORTER.

The above is the rough beneficiation of diamonds. If you want to continue to improve the purity of diamonds, we need to carry out the next step of fine selection. The main equipment includes an X-RAY SORTER or an separador electrostático to remove impurities.

 

 

Equipment Selection and Specifications

No.	Machinery List	Nº de modelo	Quantity (Set)
1	Alimentador vibratorio	3800*960	1
2	Fregadora Trommel	JXSC-1200	1
3	Belt Conveyor  (customized)	650*5M	3
4	High Frequency Vibration Screen	JXSC-1530-2	1
5	Separador Jig	JT2-2	2
6	#1Water Pump	IS80	2
7	#2Water Pump	IS150	1
9	Full Set Spare Parts	/	1
10	Full Set Cables	/	1

 

We offer a comprehensive 50TPH Alluvial Diamond Washing Plant solution for operations in Angola, delivering full factory services including flowchart design, layout planning, complete equipment provision, shipping to Tanzania, and technical support. This processing plant is specifically engineered for mining operations with alluvial diamond deposits containing sticky clay, requiring a concrete foundation prepared by the client or utilizing natural elevation differences in mountainous terrain. The plant is not recommended for ultra-hard ores without pre-treatment capabilities or for rock diamond processing (such as Kimberley Diamond), which would require additional equipo de trituración.

 

Questions & Answers

 

Question 1: What types of alluvial diamond deposits are suitable for this solution (trommel scrubber + high-frequency vibrating screen + jig separator)?

Contesta:

• This solution is a classic standard configuration for the primary processing of alluvial diamonds and is suitable for a wide range of scenarios.
• It is especially suitable for alluvial, river-valley, and coastal diamond deposits.
• It is highly adaptable to deposits with high clay content, high gravel content, and uneven diamond size distribution. Whether it’s a small-scale individual mine, a medium-sized commercial mine, or an open-pit alluvial diamond mine in a remote area of Africa, a customized solution can be provided.

 

Question 2: What are the functions of the trommel scrubber, high-frequency vibrating screen, and jig separator in the diamond processing Plant?

Contesta:

• Trommel scrubber: Cleans clay, sand, and vegetation debris from the surface of the ore. Diamond-bearing sand is commonly encased in mud clumps; without pre-washing, the clay will clog the screens and encase the diamonds, directly leading to failure in subsequent separation processes and significantly reducing equipment lifespan.
• High-frequency vibrating screen: Provides precise particle size classification of the washed ore. Diamonds have a specific particle size range for enrichment; the ore with the correct particle size is sent to the jigging machine, while unqualified gravel and coarse residue are discarded. This reduces the processing load on the jigging machine and prevents coarse gravel from damaging the diamonds.

 

 

• Separador de plantilla: Utilizes the principle of gravity separation and is the core equipment for diamond enrichment. The density of diamonds is much greater than that of ordinary gangue and sand particles. Under the action of the alternating water flow in the jig separator, the diamonds settle to the bottom of the bed, forming a diamond concentrate, while light impurities are discharged with the water flow, achieving efficient enrichment.

 

Question 3: Which types of alluvial diamond deposits are suitable for this alluvial diamond washing plant, consisting of a alimentador vibratorio, a trommel scrubber, a high-frequency vibrating screen, and a jig separator? Can it be used for weathered sand, riverbed sand, and high-clay sand deposits?

Contesta:
It is suitable for most open-pit alluvial diamond deposits, such as riverbed alluvial deposits, coastal deposits, weathered crust deposits, and residual slope deposits, and can operate stably. It is especially suitable for deposits where diamonds exist in a free state and are accompanied by clay and gravel.

• Optimized for high-clay deposits: For difficult-to-process deposits with high clay content and many mud lumps, the accompanying rotary washing machine can powerfully scrub and disaggregate the material. Combined with high-pressure water washing, it thoroughly breaks up mud lumps and removes mud and dirt from the diamond surface, preventing diamond loss due to clay encapsulation from the source, without the need for additional complex pre-treatment equipment.
• Strong particle size adaptability: It can process raw ore from 0-150mm. Through equipment classification and washing, the slurry is adjusted to the optimal feed particle size for the jig separator, ensuring effective separation.

 

 

Question 4: Logistics are difficult at remote mining sites, and are there many easily damaged parts in the equipment? Are spare parts available locally? Is daily maintenance difficult?

Contesta:
The solution uses general-purpose mining equipment with few easily damaged parts and high interchangeability.

• List of spare parts: The core easily damaged parts are only the screen of the trommel scrubber, screen of the high-frequency vibrating screen, jig separator bed screen plates, and bearings, all of which are standard specifications in the mining industry.
• Parts and maintenance: The manufacturer will provide spare parts with the shipment; moreover, we have warehouses in Nigeria, Zimbabwe, and Indonesia, and these parts can be purchased from construction machinery markets and mining parts stores in mining areas in Africa, Southeast Asia, and other regions.
• Daily maintenance only requires regular lubrication of bearings, checking screen wear, and cleaning accumulated mud from the equipment, which can be done by ordinary workers.

 

Conclusion: Client Success and Satisfaction

The implementation of this diamond washing plant has been a significant success, as evidenced by positive customer feedback following equipment delivery and installation. The plant effectively processes clay-rich alluvial material while providing efficient diamond recovery across the specified size ranges.

This case study demonstrates how properly designed processing equipment can address the specific challenges of alluvial diamond mining in Africa. By combining robust washing capability, precise classification, and effective concentration technology, our solution delivers reliable performance even in demanding operational environments.

For mining operations dealing with similar alluvial diamond deposits containing sticky clay and variable material sizes, this processing approach offers a proven path to efficient diamond recovery and operational success.