After Military Is Before Military

I am heading back to DRC after 3 weeks of military service in Switzerland. Actually my weeks were quite good, because I could do what most of male chemists would like to do: Making explosives.

The following pictures reduce it best to one sentence:

Science: Do stuff in lab that would be a felony in your garage.

In the first two weeks my task was to synthesize an explosive which could be used as an alternative. It is difficult to get recipes in scientific books, because it is quite sensible to publish them. However after I did not get any recipes in known appropriate books for that specific explosives, I did some research on the net and found some recipes by hobby chemists. It was weird to see what kind of recipes are in the net, but after some modification  I found a good way to produce some small quantity in good quality. It was very nice to be in the lab again after several years and do some real chemistry.

My third week was similar like last year. Giving a lesson to mainly foreign Military Services in how to qualify explosives by thin layer chromatography.  Next year the same will start over again (like every year). I am looking forward for it! It is great to work in this professional team.

Some Swissness

Even I am in Congo or East Africa, from time to time a few Swiss things appear:

A Swiss flag in a different way… It supposed to be the medical kit. The manufacturer does not seem to exchange the right colour order. Red-white or white-red?

Have you been: UCI Championnats du Monde at Chateau d’Oex Suisse in September 1997.

Some people like the Swiss Knife. A great invention. I never leave without it. Sometimes I fix a half  bus by using the screwdriver…

Team Uzwil: I hope they won!

Our (famous) products from Nestle, Vevey.

Bollywood movies, which mostly have a Swiss scenery. Cows, mountains…

and chalets. Sometimes you hear me shouting: “Oh my good, that looks like Bern…”

Swiss chocolate, made in Kenya 😉

SGS Schweiz – Société Générale De Surveillance SA

When I was recently at the mine and I just had about 1 hour spare time, my friend brought me on the idea to visit the SGS lab. The idea was simple and great, because SGS is a Swiss company and when do you have the chance to get in touch with something Swiss in the bush of Congo? As my skin color is kind of all access card to various buildings, it was easy to enter it and pass the security control. It was like always: “Confident occur in complete ignorance”. However, after stepping in the building, it was asking for the manager and was shown him to his office. After a short introduction of myself (Swiss and chemist) he got very talkative and started to explain in detail what SGS and his lab is doing. It was interesting to listen to him and after a half an hour he offered me to get a tour trough the lab. I could not refuse…

SGS (www.sgs.ch) is the world’s leading inspection, verification, testing and certification company. The company has 1500 labs and about 75’000 employees. SGS says about hisself: “Wherever you are in the world, in whatever industry, you can rely on our international teams of experts to provide you with specialized business solutions to make your business faster, simpler and more efficient. We partner with you to offer independent services that will help you reduce risk, streamline your processes and operate in a more sustainable manner.”

In Kibali Mine, SGS is responsible for testing the samples out of the ground on the gold and silver content by F-AAS (flame atomic absorption spectrophotometry). The process is quite simple and is shown below. By the wa, all the gold which is mined in Kibali goes directly to Switzerland. Interesting…

The to be tested stone and sand sample has to be crushed to a very fine powder (80-90%<75 μm). For that the grey machines are used to crush the stones in rough sand of a few millimeters.

Afterwards the sand has then to be further crashed in a very fine power by the yellow machine.

The sample with litharge (“lead”) and glass fluxes was …

… charged at 850°C (in a crucible) in a muffle furnace and maintained well above 1000°C for 30-40 min until a complete fusion occurred. The lead circulates through the molten mass and collects the precious metal forming Au-Ag-Pb alloy, ….

… which is recovered as a button after cooling and separation from the glassy slag containing base metal and other impurities.

Bone ash and marborite cupel (?) heated to 1000°C are charged with the lead button. This process results in a precious metal bead, …

… which is parted by dissolving in nitric acid. After dissolving in nitric acid, everything except the gold is dissolved. In order to get rid of the “disturbing” silver, the hydrochloric acid is added, which now dissolves the gold (aqua regia), but precipitate the silver as insoluble AgCl. The reagent can then be easily measured by F-AAS for the gold content in a ppb-ppb range.