Fact finding mission to Katanga, Southern D. R. Congo

A mission was carried out in Lubumbashi aiming at introducing mercury-free gold mining techniques for small-scale gold miners in Katanga, D. R. Congo. The mission was initiated by Professor Celestin Nkulu, University of Lubumbashi and Senior Research Scientist Peter Appel, AppelGlobal at a conference in Denmark mid-2017. The aim is to reduce the major release of mercury from small-scale gold mining in D. R. Congo. This is in harmony of the D. R Congo signing of the Minamata Convention in 2014.

The mission was carried out during the period March 5th to 16th 2018 with a field trip to Kimpese small-scale gold mining community in Katanga.

The first days were spent with discussing the aims of the project and to obtain appropriate permissions on signed documents from relevant authorities. A meeting with the Minister of Health was held. A planned visit with the Governor was unfortunately cancelled. Getting the necessary permissions took the better part of the first week.

The group consisted of

Prof. Celestin Banza Lubaba Nkulu, University of Lubumbashi

Dr.  Tony Kanyembe Kitenge             University of Lubumbashi

Dr. Paul Musa Obadia                         University of Lubumbashi

Dr. Albert Mutoka                                  University of Lubumbashi

Dr.  Michel Muka                                   University of Lubumbashi

Peter Appel                                            AppelGlobal.com

The period where for this fact finding mission was unfortunately in the rainy season. This meant roads were slippery. The road to Likasi, which is the second biggest town in Katanga was fine. About an hour’s drive further from Likasi the road started to get slippery and between the village of Kambove and Kimpese the road was very troublesome. Arriving in Kambove we were requested to pay several visits to different authorities and each place the authorities had to sign the back site of our permission document. This is a very time consuming process, but it is a must during the first visit to an area. Between Kombove and Kimpese we passed a small village. Here again we had to pay courtesy visit to the local head of village. Finally, we ended in Kimpese where the small-scale gold mines are active. We were guided around by a head of the site.

We had only a short time to go through the processing sites. Gold is mined from placer as well as from hard rock. Placer processing was standard with screening the pebbles away and then let the fine material down a launder covered by a piece of cloth. The water was added by buckets and therefor there was not constant flow of water down the decline (see photo below). A large part of the gold especially the fine gold will obviously be lost.

Area were placer gold is being recovered. Two launders in the foreground

We did not see the mining site for hard rock mining. The mined rocks were carried down to the processing site where it was manually crushed. Subsequent milling took place in larg drums similar to the ones seen many other places in Africa. It is made by the local blacksmith and is not very long lasting as seen by many repairs of the drum. It is dry milling.

After milling the fine material is added to the top of the launder and buckets of water flush the material of the cloth covering the decline.

The carpet is subsequently washed in a tub and the heavy minerals are thoroughly mixed in a pan with mercury. When all gold has been amalgamated the amalgam is squeezed and the amalgam is heated in a clay bowl

March 14. The group met at the university and discussed the topics which shall be investigated in a future project. Likewise, was the duration of a future project was discussed. The agreement was to aim at either three or five years.

March 15. A conference was held where I gave an extended presentation of the mercury-free gold extraction method. Several questions and comments were brought from the audience.

Dry milling of crushed hard rock gold ore

Sieve in the foreground for removing non-milled ore











The set-up at Kimpese is very similar to small-scale gold mining sites in other parts of Africa e.g. Tanzania and Mozambique.

For an upcoming project to at teach and train the mines to extract gold without using mercury following model is recommended. The model has just been used in Cabo Delgado area of Mozambique with success. A report on the Mozambique project can be obtained.

Man power:

A group of eight to ten miners to be selected among the miners working in the area. The chosen miners get detailed information on what the mercury-free method entails. They shall view demonstration of the method. This will be done by Leoncio Na-Oy a small-scale gold miner from Philippines. Leoncio has together with me introduced the mercury-free method in a number of countries such as Sudan, Mongolia, Peru, Indonesia and Philippines. After demonstration the chosen miners shall carry out the gold extraction repeatedly until they know the method by hart. Leoncio will subsequently chose a small number of the taught mines and those shall in the future act as trainers for their fellow miners.


A small modification of the processing lines presently used for gold extraction from hard rock gold ore. Details can be provided. This part is low low cost.

An alternative solution is to modernise the milling done at Kimpese.

The milling done by the large drums has three main problems:

  • The mill creates large amounts of dust which will cause stone lungs on the miners
  • The mill causes hearing problems because high noise level
  • The mill creates large amounts of very fine gold flakes which cannot be recovered and thus reduces gold recovery for the miners

It is thus suggested that introduce wet milling of the gold ore in smaller drums.