In this paper we consider problems which stem from production planning processes in the chemical industry. Many of these problems may be formulated as mixed integer linear programs, Since it is a big deal to obtain an optimal solution of this model in a reasonable amount of time, the design of fast and efficient heuristics is very important for practical purposes. In this paper we investigate heuristic approaches which consist of different rounding strategies based on an optimal solution of the corresponding linear relaxation of the integer program. Computational experiences on practical data are reported.