Portland cement clinker production is a complex technological process in which raw materials, limestone and clay mixed in the appropriate ratio pass through a variety of highly complex and demanding processes, including drying, grinding, homogenizing at the stage of raw material preparation. In the process of preparing the clinker raw material, it passes through a heat exchanger (heated by exhaust gas from the rotary kiln), whereby further heat of the raw material is carried out at higher temperatures which enable the dihydroxylation and calcination process to take place just before entering in the rotary kiln. In the rotary kiln the raw material is heated at the much higher temperature that ensures the sintering reaction and it allows the formation of the major minerals such as Tricalcium silicate ( 𝐶 3 𝑆 ), Dicalcium silicate ( 𝐶 2 𝑆 ), Tricalcium aluminate ( 𝐶 3 𝐴 ) and Tetracalcium Aluminoferrite ( 𝐶 4 𝐴𝐹 ) mineral phase. The weight and shape of each mineral type and their physical and chemical properties depend to a great extent on the quality of the cutters obtained, that is, in the further stage of cement production, and the final properties of the cement produced which reflect on strength, heat of hydration, chemical resistance, etc. In this paper, portland cement clinker was produced on a semi-industrial furnace using standard materials used on industrial furnaces with one difference that the furnace filling was discontinuously made with raw material that did not undergo preheating processes and the raw material was added as a granule (semi-dry process). The resulting clinker was characterized by microscopy and X-ray diffraction. The results indicate the achievement of reaction conditions that ensure the production of clinker. The distribution and size of the crystalline minerals formed in the clinker as well as the content of free lime indicates that the synthesis process could take place with a longer retention of the raw material in the furnace to allow less free lime and possibly higher mineral content.