What is the reason behind Africa is poorest country in the world, if they have most rich resources

To be fair, Africa is rich in some resources, largely rare earth metals. Botswana is the world’s second largest diamond producer, Rwanda is the eighth largest tungsten producer, the DRoC produces 70% of the word’s cobalt, South Africa produces the most chromium and platinum as well as the second most palladium, etcetera. South Africa produces more aluminium than Mozambique.

Mozal, their aluminium smelter got two potlines while Hillside Aluminium in South Africa got 2.5 potlines ( over 700k tons pa).

Just a small details but still miniscule compared to Chinese or Indian or middle eastern smelters.

But everyone wants a piece of DRC. Even the countries that would feel disgusted having DRC refugees on their shoreline still want a piece of pie from DRC. So one way is they topple the government that doesn't kowtow to their interest and once they put in a puppet leader, weapons pour in to suppress protests and eventually you get to have a lawless failed country where even the wild west is a child play.

Most of Africa is not as resource rich as it is believed. It is just their scarce few resources were denied access to their local population, and carted off to foreign countries giving an illusion of resource richness. To get rich a country needs four strong fundamentals: a high literacy rate so that people grow up to have skills, decent health system so that they are healthy enough to contribute to development, women being treated more or less at par with men so the place is not deprived of productivity of half of its population, and finally rule of law/political system which allows enough freedom to people to prosper. 

For instance, the continent’s largest oil producer — Nigeria — produces about 1.5m barrels per day. This sounds a lot, but is just 10% of what US produces and again much less than Russia or Canada. If Nigeria grows its middle class, it won’t have sufficient oil for its own population. African countries lacked the option to money launder for the Nazis. If you are a small country that helps launder money — Swiss, Singapore, Mauritius, Cayman — you can get rich.

That said, Switzerland is not a desert. Plenty of water, farm land and cattle. Hydro energy (cheapest form of energy) is plentiful providing a rich base for industries.

Apart from the industries that use hydro power the country also uses its location for tourism and banking. For a 8 million people town that is plentiful of resources.

Singapore has a great natural harbour (one of the best natural resources) yielding great trade and fishing. For its tiny population that is quite sufficient. Morocco holds 75% of the phosphate reserves of the world, and is ranked third or second in the world in its production... Silver and lead production in Morocco are the highest in Africa.

Also Morocco exports more than 600,000 tonnes of seafood every year. Locals can't afford buying seafoods, because Europeans can pay more for it than what we can afford. 600,000 tonnes is almost 20kg per citizen! The only thing I can afford is sardines, I eat it only once in a month.

Morocco exports millions of tonnes of agriculture products every year.

Morocco is the world's largest exporter of hashish, the resin from cannabis. According to the World Customs Organization, Morocco supplies 70% of the European hashish market. Although statistics vary widely, hashish production is estimated to be 2,000 metric tons per year, with up to 85,000 hectares devoted to cannabis production, with a market value of $2 billion.

It's not lack of resources that made Africa poor, but corruption, interference of France on the policies of the African countries, greedy officials and so on…

Just imagine that they cut water from us to keep the farms which are owned by the officials running! You open the water faucet and there's no water most of the year. 

Most of Africa’s population don’t have oil, coal or other key energy access. And nuclear power is nearly absent from most of the continent.

Here is water — the most critical resource for mankind. Most of the continent is either in red or yellow (deserts). The dark blue zone in the center is rainforests and not as suitable for farming. That leaves very few parts of Africa that are suitable for large scale farming.

This leads to this map of farm lands.

And that brings the food production. This chart is a bit old, but the ratio has not changed a lot.

Let’s come to metals. The continent’s largest producer of iron ore — South Africa — produces about 77000 tons/year a third of India’s and less than 10% of Australia’s. And most of rest of Africa have hardly any iron ore mines.

The continent’s largest producer of Aluminium — Mozambique — produces 1/7 of India and 1/70 of China. Most of Africa have hardly any aluminium production. The continent as a whole have very limited Bauxite reserves.

In copper, the continent does a little better — Congo and Zambia have decent copper resources — but a fraction of what a major producer like Chile produces.

People think of diamonds, gold etc as profitable. But, they are not. South Africa and Botswana each export about $2billion a year worth of diamonds and they cost a lot to mine. India and Israel make far more money off these diamonds than the two African producers. Diamond Exports by Country $2b is not bad, but not world changing either. To put that in context, Norway exports $49b in Oil & Gas and they are fairly cheap to extract too. Whenever you think Africa has gold, diamonds, lithium etc, convert that to dollar terms and you would find it pretty average.

The countries in the continent that have some natural resources — South Africa, Nigeria, Botswana — are also among its richest. And the countries that are pretty poor also tend to be ones without a lot of resources.