In this article, we report on the mass production of carbon nanotubes using a continuous production system based on a rotary tube furnace. At first, we have optimized the composition of the metallic nanoparticles. Bimetallic Fe2Ni and Fe2Co alloys exhibit higher catalytic activity than pure Fe, Co or Ni. Then, catalyst production process has been modified for the preparation of large quantity of catalyst with low aggregation suitable for large scale synthesis of CNTs. A production rate of about 1.2 kg per day has been achieved. This is yielding to a cost production of less than $1 per gram. Finally, we show that the CNTs growth can also be obtained on naturally occurring calcite support for further cost reduction of the synthesis. Quality of the CNTs produced has been established by measuring their mechanical properties using AFM. Young's modulus of the CNTs can be as high as the ideal value of 1 TPa. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim