RAW MATERIAL AND CEMENT GRINDING

IN THE CEMENT WORKS OF THE FEDERAL REPUBLIC OF GERMANY THE HAMMER CRUSHER IS PREFERRED FOR THE PRIMARY CRUSHING OF THE RAW MATERIAL. FOR COMBINED DRYING AND GRINDING, INSTALLATIONS COMPRISING TUBE MILLS--OFTEN WITH HEATED HAMMER MILLS PLACED BEFORE THEM--ARE PREDOMINANTLY USED. SPRING-TYPE MILLS, WHICH AT THE PRESENT TIME PRODUCE ABOUT 12% OF THE INDUSTRY'S RAW MEAL REQUIREMENT AND CAN HAVE LARGE QUANTITIES OF EXIT GAS PASSED THROUGH THEM, REQUIRE MORE COARSELY LUMPY FEED MATERIAL THAN TUBE MILLS, AND OPERATE WITH LOWER POWER CONSUMPTION FOR PURELY EFFECTING SIZE REDUCTION. FOR THE COMBINED DRYING AND GRINDING OF VERY MOIST AND STICKY RAW MATERIALS THE AEROFALL MILL IS NOW USED ALSO IN CEMENT WORKS. CEMENT GRINDING IN MILLS MORE THAN 2.8 M IN DIAMETER IS PERFORMED MAINLY AS A CLOSE-CIRCUIT OPERATION. ALMOST HALF THE QUANTITY OF CEMENT PRODUCED COMES FROM CLOSED-CIRCUIT GRINDING INSTALLATIONS. THE LARGEST CEMENT MILL IN THE FEDERAL REPUBLIC OF GERMANY IS 4.0 M IN DIAMETER, 14.0 M LONG, AND HAS A DRIVE POWER OF 2700 KW. THE TOTAL CAPACITY OF ALL CEMENT MILLS IS ABOUT 42 MILLION TONS OF NORMAL-HARDENING CEMENT. RECENTLY DEVELOPED TYPES OF RECIRCULATING AIR SEPARATOR, A NEW FORM OF MILL LINING, AND GEARLESS DRIVE FOR LARGE TUBE MILLS PROMISE IMPROVEMENTS IN TERMS OF PROCESS ENGINEERING AND ECONOMY. GRINDING AIDS ARE ADVANTAGEOUS MORE PARTICULARLY FOR THE GRINDING OF CEMENTS WITH HIGH SPECIFIC SURFACES. BECAUSE OF THE MANY INFLUENCING FACTORS INVOLVED, ASSESSMENT OF THE PERFORMANCE OF GRINDING INSTALLATIONS IS DIFFICULT. BASIC INVESTIGATIONS CONFIRM THE TECHNICAL ADVANTAGE OF EXTENSIVE PRELIMINARY REDUCTION PERFORMED OUTSIDE THE TUBE MILL. /AUTHOR/

• Supplemental Notes:
  • Vol 57, No 2, PP 63-72
• Authors:
  • SCHNEIDER, H
• Publication Date: 1968-2

Media Info

• Serial:
  • Zement-Kalk-Gips

Subject/Index Terms

• TRT Terms: Cement; Crushers; Drying; Grinding; Hammers; Manufacturing; Raw materials
• Subject Areas: Highways; Materials; Vehicles and Equipment;

Filing Info

• Accession Number: 00212627
• Record Type: Publication
• Files: TRIS
• Created Date: Jul 22 1994 12:00AM