Kawah Ijen or Ijen Crater is volcano which has the largest acided lake in the world, about 20 Km wide and the volume of the crater proximately around 36 cubic hectometres (29,000 acre•ft).
The summit of ijen crater is about 2.799 meter high, it took and effort for peoples to reach at the top. Mostly it take two-hour hike is required to reach rim of the crater (1.5 kilometers) from the summit, and 45 minutes to hike down to the bank of the crater, a guide necessary.
The caldera or the lake of Kawah Ijen harbors has turquoise colored, the color it came from acidic crater lake that leaks sulphurous gases constantly then mix the the water spring that come of from bottom of crater area.
at Nigh the hot gases burn out to emit an amazing blue glow unique color in some part of the bottom of crater, it well known as "Blue fire" pure fire that emerge beneth the earth.
the blue fire emerge because the gases and also liquid sulphur emerge from the cracks in the volcano come up with high pressure and temperature (up to 600°C) and when it contact with the air suddenly it ignite and burn as it flows down the slopes among the pipe giving the feeling of blue lava flowing.
Kawah ijen is becoming very well known in the world, as the only one natural blue fire. But not many peoples know that actually ijen is not only amazing touristic destination. From Dutch colonial age, Kawah Ijen is work place for sulphur miner.
The liquid sulphur that leaking from beneath the earth channeled through a network ceramic-steal pipe line, the liquid with bright red color molten, pours slowly through ceramic-steal pipelines, then end of on the ground and liquid sulphur mix with Oxygen it condense instantly then change the color becoming bright yellow when it cools down.
All then miner have to break the yellow cooled sulphur into pieces, the nearby crater in very dense of sulfuric smoke (gas) that emerge of crater which can make peoples hardly to breath and also make the eyes itchy. The miner have to deal with such harsh enviromment an able to collect sulfur put in the their bamboo basket and carried it down the hills. Mostly the miner carried weight of basket up to 60 Kg - 100 kg and they carried it twice a day.
The miner carried it down, weight it up at post point, then the officer (from private company) note how much they carried in their basket, every 1 kg of sulfur paid for 800 - 900 IDR.
The workers work in extremely hazardous condition with insufficient protection. Most of them suffers from numerous respiratory problems due to breathing toxic fumes day in and out. At times they work at night under to escape the heat of the sun, and to earn extra income.
