Methods of plugging and abandoning a well using compositions comprising cement kiln dust and pumicite

A method of plugging a well bore for abandonment comprising:

• placing a plugging composition in the well bore, the plugging composition comprising:
• a cementitious component consisting essentially of cement kiln dust, pumicite, and lime, and
• water;
• and
• allowing the plugging composition to set and form a plug.

A method of cementing comprising:

• providing a sealant composition comprising:
• cementitious components comprising:
• cement kiln dust in an amount of about 5% to about 100% by weight of the cementitious components,
• pumicite in an amount of about 5% to about 100% by weight of cementitious components, and
• 0% to about 24% of Portland cement by weight of the cementitious components, and
• water;
• and
• allowing the sealing composition to set.