Abstract: The present invention provides a process for preparing a precipitated calcium carbonate product comprising the steps of: (a) preparing an aqueous suspension of precipitated calcium carbonate seeds by carbonating a suspension of Ca(OH)2 in the presence of 0.005 to 0.030 moles of Sr, in the form of Sr(OH)2, per mole of Ca(OH)2, (b) dewatering and dispersing the precipitated calcium carbonate seeds prepared in step (a) to obtain an aqueous suspension of precipitated calcium carbonate seeds having a d50 of less than or equal to 0.1 to 0.3 ?m and a BET specific surface area of 10 to 30 m2/g, and (c) forming an aqueous suspension of a precipitated calcium carbonate product by carbonating a slurry of Ca(OH)2 in the presence of 0.

Abstract: The present invention provides a process for preparing a precipitated calcium carbonate product comprising the steps of: (a) preparing an aqueous suspension of precipitated calcium carbonate seeds by carbonating a suspension of Ca(OH)2 in the presence of 0.005 to 0.030 moles of Sr, in the form of Sr(OH)2, per mole of Ca(OH)2, (b) dewatering and dispersing the precipitated calcium carbonate seeds prepared in step (a) to obtain an aqueous suspension of precipitated calcium carbonate seeds having a d50 of less than or equal to 0.1 to 0.3 ?m and a BET specific surface area of 10 to 30 m2/g, and (c) forming an aqueous suspension of a precipitated calcium carbonate product by carbonating a slurry of Ca(OH)2 in the presence of 0.

Abstract: The present invention provides a process for preparing a precipitated calcium carbonate product comprising the steps of: (a) preparing an aqueous suspension of precipitated calcium carbonate seeds by carbonating a suspension of Ca(OH)2 in the presence of 0.005 to 0.030 moles of Sr, in the form of Sr(OH)2, per mole of Ca(OH)2, (b) dewatering and dispersing the precipitated calcium carbonate seeds prepared in step (a) to obtain an aqueous suspension of precipitated calcium carbonate seeds having a d50 of less than or equal to 0.1 to 0.3 ?m and a BET specific surface area of 10 to 30 m2/g, and (c) forming an aqueous suspension of a precipitated calcium carbonate product by carbonating a slurry of Ca(OH)2 in the presence of 0.

Abstract: The present invention provides a process for preparing a precipitated calcium carbonate product comprising the steps of: (a) preparing an aqueous suspension of precipitated calcium carbonate seeds by carbonating a suspension of Ca(OH)2 in the presence of 0.005 to 0.030 moles of Sr, in the form of Sr(OH)2, per mole of Ca(OH)2, (b) dewatering and dispersing the precipitated calcium carbonate seeds prepared in step (a) to obtain an aqueous suspension of precipitated calcium carbonate seeds having a d50 of less than or equal to 0.1 to 0.3 um and a BET specific surface area of 10 to 30 m2/g, and (c) forming an aqueous suspension of a precipitated calcium carbonate product by carbonating a slurry of Ca(OH)2 in the presence of 0.

Abstract: In a steel frog for rail crossings and rail switches, the frog point or, respectively, the surface of the frog being travelled upon by the wheels consists of an age-hardening steel having the composition______________________________________ C 0.01 to 0.05% Ti 0.1 to 1% Si 0.01 to 0.2% Cr 0 to 13% Mn 0.01 to 0.2% Al 0 to 0.2% Co 0 to 15% B 0 to 0.1% Mo 1.5 to 6% Zr 0 to 0.1% Ni 7 to 20% ______________________________________The frog is manufactured such that the surface being travelled upon by the wheels is applied by build-up welding onto a base body consisting of nominal rail steel.

Abstract: A rail switch in which two wing rails are engageable with a frog in alternation, characterized in that guide members are provided, which are held in position relative to the wing rails and extend under and are engageable with the frog or parts rigidly connected to the frog to prevent an upward movement of said guide members.

Abstract: Railway switch for Vignoles rails, comprising a frog tip and a pair of wing rails arranged for swivelling movement, one of said wing rails engaging the frog tip in its end position and being supported in this position in direction of engaging the frog tip by means of movable supporting members resting against the railway sleepers, noting that the movement of the supporting members and of the wing rails is being effected in mutual dependence, that the supporting members are guided on the railway sleepers in longitudinal direction of the corresponding wing rails and are cooperating with abutments protruding from the wing rails and preferably being fixed to the web of the wing rails, and that the supporting members are formed of one supporting rod for each associated wing rail, said supporting rod comprising, in addition to the supporting surfaces serving for supporting the abutments, recesses giving free the wing rails, characterized in that the push-rod serving the purpose of switching over the railway switch

Abstract: Railway switch for Vignoles rails, comprising a frog tip and wing rails arranged for swivelling movement, each of the wing rails engaging the frog tip in a respective end position and being supported in this position by supporting members resting against the railway sleepers, the movement of the supporting members and the movement of the wing rails being effected in mutual dependence, the supporting members being guided in longitudinal direction of the corresponding wing rails by guide members on the railway sleepers and the supporting members cooperating with abutments protruding from the wing rails and fixed to the web of the wing rails.