Quickly releasable liner bolt

A nut and bolt system to maintain assembled a liner plate on a grinding mill wall, said liner plate having a first through aperture opening into a recess, said mill wall having a second through aperture with said first aperture being aligned with said second aperture;

• said nut and bolt system comprising:
• a liner nut having an exterior surface shaped to mate with said liner plate recess to thereby prevent rotation of said nut relative to said recess, said liner nut further having a protruding portion which is dimension to extend through said recess and first aperture and into said second aperture to maintain said first and second apertures aligned, said protruding portion having a blind threaded hole,
• said liner nut further having a protruding portion which is dimensioned to extend through said recess and first aperture and into said second aperture to maintain said first and second apertures aligned, said protruding portion having a blind threaded hole,
• a liner bolt having an elongate shank with two ends, one of said ends terminating in a head having a transverse dimension greater than said shank and being shaped to be engageable with a tool to permit said bolt to be rotated, said shank having a transverse dimension less than the size of said first and second apertures to permit said shank to pass therethrough, and the other of said shank ends being threaded and being threadably engaged with said nut such that said head bears against one side of said mill wall to hold said liner plate against the other side of said mill wall;
• wherein operation of said grinding mill wears said liner plate requiring eventual replacement of said liner plate and producing fines which enter said recess and cement said nut to said recess, and
• wherein said bolt can be rotated to disengage said shank from said cemented nut to permit said bolt to be withdrawn from said mill wall, said liner plate with liner nut cemented thereto being discarded and said liner bolt being retained for engagement with a second liner nut and second liner plate to retain the same newly assembled with said mill wall.